Firstly, there are three main types of pregnancy tests:
- Cartridge test--Any test which yields two lines or a plus symbol and is houses in a plastic case (cartridge) with a window where the result is viewed. Available in pink dye and blue dye. Sensitivity ranges from 10 mIU and up.
- Test strip--similar to a cartridge test, but without the case and only available in the two lined result. Sensitivity ranges from 20 mIU and up.
- Digital test--a cartridge test with a digital readout of either "Yes/No" or "Pregnant/Not Pregnant". Sensitivity starts at 50 mIU.
So when should you use a pregnancy test? Well, assuming you have a good idea of when you ovulated, implantation is likely to occur 6-12 days after ovulation (on average). HCG needs a few days to rise to a level that can be detected on a home pregnancy test. The sooner you test, the higher the likelihood of a false negative result. We know that it's very hard to wait for the answer!! We recommend not testing earlier than about 9 DPO, and to try to keep in mind that a negative result before your missed period might not mean that you aren't pregnant. With both my second (miscarriage/chemical pregnancy) and third round of BFP pregnancy tests, I didn't get a positive result until 14 or 15 DPO, and believe me, I was testing early!
Most pregnancy test directions will also recommend that you take the test with first morning urine. This is because it is thought that it will contain the highest concentration of HCG. I definitely agree with this, however, some women find that this isn't true for them. Some women have more accurate results when testing in the evening. Try both methods and see what works for you.
So we're down to how to use a pregnancy test properly. The most important thing is the read the directions very carefully. Remove the test from it's wrapper and remove cap if applicable. Hold the "wick" end of the test in the stream of urine for the time listed in the instructions (this varies by brand and sensitivity) or collect a sample in a clean cup and dip the test (again, check directions, this time may differ depending on your method of testing). Place the test face up on a flat surface and WALK AWAY SLOWLY!!!
Wait the amount of time indicated in the directions and take a peek. And remember NOT to trust any result that shows up AFTER the amount of time listed on the directions (usually about 10 minutes). Lines may show up after the time limit, even in non-pregnant women.
So that's the skinny on pregnancy tests! We take them, some of us even take photos of them and scrutinize them using photo editing software! We toss them in the trash and pull them out hours later to look at them again (why do we do this??). We curse them, threaten to take a red sharpie to show them JUST what that second line should look like, we hoard them, and we take far to many of them in a 24 hour period. What else do you want to know about pregnancy tests???