If we mention bulk pregnancy tests, a lot of people are going to be confused. Why would you need more than one? Are you trying to sell them, and need to buy them cheap?
No, actually. Bulk pregnancy tests are useful for a certain subset of women who are trying to conceive. Buying a single test every few days or weeks, when you're struggling to conceive, can get expensive and tedious. Worse, there's a bit of social stress involved; what does the cashier at your local CVS think the fifth time you come through the line with a test? Sure, you could explain it, but why would you? It's none of their business.
Cost is, as usual, the driving factor here. You can't exactly go into your doctor every week to see if this attempt took hold. Going into the local pharmacy to grab a test is expensive – they can be $5 each, $8 for two, or some other high price. It's also dangerous these days; you probably want to limit the number of times you go out, especially to a place where sick people tend to visit more often. 
Sure, you can try to be rational about things, and ration your tests. Technically, you're not realistically going to need more than 1-2 tests per month. But that's rationality. When you're trying to get pregnant, rationality often flies out the window. Especially if you've been trying for months with no success; everything you do starts to twist towards ways to boost fertility or help conception.
At this point, you start looking for options to cut back on costs, stress, and other potentially negative factors. Instead of spending $5+ on a fancy branded pregnancy test, you might as well go with cheaper, doctor's-office-grade tests.
You didn't think your doctor is buying tests at $5 each, did you? If you've ever had a test performed in a doctor's office, chances are you've seen the tests they use. They're stripped down, simple, and easy to use. They don't have fancy plastic shells and extra markings, sure, but they don't need those. All they need is the simple test itself and just enough shell for you to hold while you use it.
What's the Difference Between Cheap and Expensive Tests?
You're likely concerned that a "cheap" test isn't a good test. If it's so much less expensive, they had to cut corners somewhere. Did they cut corners on the quality of the test?
There are undeniably some differences between cheap and expensive tests, but efficacy is not one of them. At least, not really. So what are the differences?
Sensitivity. The cheaper tests tend to be less sensitive than the more expensive tests. When you become pregnant, as soon as an embryo implants, your body starts producing more and more of the hormone hCG, which can be found in urine. This hormone shows up immediately, but only in low levels. It takes anywhere from 7-14 days for enough of the hormone to be produced that it can be detected on a pregnancy test.
More expensive brands tend to be more sensitive to this hormone. They'll be more likely to detect the presence of hCG closer to the 7-day mark, compared to cheaper tests, which might take until the 14-day mark. Some of the most sensitive tests can detect even earlier, in the 5-6 day range. Rarely, though, are the cheaper tests going to be so insensitive that it takes more than 14 days.
Virtually all pregnancy tests will work fine after a certain point. It's very rare that you'll find a pregnancy test brand that simply doesn't work.
Speed. Unrelated to how sensitive the test is, the speed of the chemical reaction used to detect hCG can vary. Cheaper tests tend to take longer – a couple of minutes, at most, usually – to give you your results. More expensive tests might give you results within 30 seconds.
Note that this isn't always the case. Some cheaper tests can give you results in seconds as well, while some more expensive tests might take longer. In part, this is about marketing, even; some people find the "instant-read" to be more valuable, while others feel like getting results too soon might mean they're not always accurate, and that taking longer means it's better. It comes down to individual perceptions and marketing from the test brand to determine which is better. The secret is, they're both find.
Design features. This is the big one. The core of every pregnancy test is basically just a little strip of a cloth-like pad. The pad has antibodies and enzymes built into it (basically soaked in a solution and left to dry before being packaged). When urine soaks one end of the pad, any hCG present will bind to those antibodies. A wick on the other side starts to pull the antibodies towards it, and they will pass over the test and control lines. Other antibodies in the test line also bind to the antibodies that are passing through, which colorizes the line. It's pretty tricky, but you can read more about it here.
That strip is technically all you need for a test. However, using this thin, flexible strip as a test isn't very easy. It's hard to hold and it's hard to be, well, accurate when soaking it. That's why most tests have a plastic shell. This shell does two things.
- It gives you something to hold. The strip that is the actual test doesn't need to be very large, but a small strip is hard to hold and use effectively, so a larger plastic case makes it easier to handle cleanly.
- It protects most of the strip. If you were to urinate on the test strip too, erm, wildly, it won't operate properly. The plastic case of an expensive pregnancy test only leaves the tip of the test exposed, so it's impossible to contaminate it.
Results presentation. A test typically is just two lines, one that exists and one that is invisible until it binds to hCG. It's all you really need to tell whether or not the test is accurate, but some people like better presentation. Some of the fancy plastic shells have extra markings on them, and some of them even have little digital readouts, though the digital readout is still just reading the results from the pad the same way the chemical line works, so it's not really any better.
Occasionally, if you're testing too early, the cheaper tests will be harder to interpret. The line you're looking for might be faint, or it might take a while to show up. Usually, this isn't a problem with the test, though; it's more a problem with testing too soon. The ideal time to test is the same time you're missing your first period after conception, which itself is a pretty big (but not sure-fire) indicator that you've done it.
Quantity. Of course, quantity in the package is always a factor. Some of these packages you get for $8 at CVS will only have one fancy test in them, while others will have from 2-5 in them. You rarely find more than that in a box over the counter at a retail store, however.
Where to Buy Cheaper Pregnancy Tests
If the baseline is $8 at CVS for a single test with a fancy digital readout and "results within seconds" and other such features, where can you get cheaper versions of a test? You have a lot of options.
First, you can just look for higher quantity packages at your local box stores. You can find boxes with up to 5 tests for around $10 on the low end. Just make sure you're getting actual pregnancy tests; some of these boxes are ovulation kits instead but include 1-2 pregnancy tests as well. These, of course, aren't really what you want.
A second option is going to a local dollar store. Here, you can find the same kind of tests you get at a pharmacy, except instead of $8 for 1-2 tests, it's $1 for 1-2 tests. This is obviously quite a bit cheaper, and while the tests themselves might use less plastic and won't have the digital readouts, they're still just as accurate and just as effective.
Finally, of course, you have the obvious option: just go to Amazon. Amazon sells bulk cases of pregnancy tests for around the same price as buying 1-2 packs of tests at your local CVS. For examples:
- This listing is a 25-pack of tests for under $10. The unit price per test is only 36 cents each.
- This listing is a box of 50 test strips for $15, which works out to be just under 30 cents per test.
- This listing is a box containing 55 tests, which is only 27 cents each.
Now, of course, the pricing varies based on the whims of Amazon, the seller, and what bonuses you have as an Amazon customer. You can shop around and get a similar set for cheaper if you're patient enough. Also, note that none of those links are affiliate links; we're not benefitting from recommending those products, we're just using those listings as examples. Shop around as much as you want.
It's also worth mentioning that many of these tests work differently than your normal plastic-enclosed tests. These are raw strips with no casing. You're meant to pee in a cup and dip the test in it, rather than simply pee on the test. It's a little more complicated, with a slight possibility for error, but once you get to know how to use them, it shouldn't be too bad.
You can also get the same bulk tests directly from the manufacturer in some cases. For example, the third listing above can also be found here directly from the seller's site. As of this writing, it's a couple of dollars cheaper from the seller's site than from Amazon, but of course, you need to give your payment information to that site rather than just to Amazon, so you might not trust it as much.
What About DIY Tests?
There are also a variety of home remedies you might be tempted to try as a DIY pregnancy test. 
You might have seen any of these recommended by various blogs around the internet:
- The bleach test. Pee into a cup and then add some powdered bleach and mix. If it fizzes, you're pregnant, and if it doesn't, you're not.
- The sugar test. Put a tablespoon of sugar in a cup or bowl, and add a tablespoon of urine. If the sugar clumps up, you're pregnant, and if it dissolves, you're not.
- The toothpaste test. Squeeze a couple of tablespoons of any white-colored toothpaste into a container, and add some urine. If it changes color and fizzes up, you're pregnant.
- The vinegar test. Put two tablespoons of white vinegar in a container and add some urine. Mix it, and if it changes color and bubbles, you're pregnant. If not, you're not.
The idea behind all of these DIY tests is that the hormone hCG that indicates pregnancy will affect the chemical reaction between urine and another substance, usually by making it fizz.
The trouble here is that this isn't really accurate. Urine contains uric acid, which when mixed with a lot of common ingredients, can fizz up. It has nothing at all to do with the hCG in the urine, and indeed there's no science to back up these DIY tests.
Nothing is stopping you from trying out such a DIY test, but keep in mind that they will be much harder to interpret and can have a very high rate of false results. We recommend just buying some bulk tests and having them around for as long as you need, and don't bother wasting your cooking ingredients, toothpaste, or whatever else some blog tells you will work.
