How accurate are preganancy tests?

Like the ones you buy at local drug stores (i.e. Rite Aid)
Also when is best time to take one, as to ensure accurate results?

They are very accurate, when used appropriately.
If the test is done two early (less than two weeks after ovulation) it could be negative.
This is not a FALSE negative, it's just too early to do the test.
Most urine tests are positive at an HCG of 50, sometimes even 25. This would correlate with a gestation of around 4 weeks and a few days by ultrasound.
By 5 weeks, a test would definitely be positive, unless there is a blighted ovum, causing a drop in HCG -- this means that a miscarriage is about to happen.
There's always a chance that something could be wrong with the test, or a lab error, but that's pretty unusual. There's usually a logical explanation for a "false" negative, and it's usually just that it was done a few days too early.
Testing too early wastes your money and makes you crazy!
Good luck!

it's 99.9% accurate!

The best time is in the morning when you 1st go to the bathroom.They are very accurate,if there is a very faint line it still meen you are pregnant.any pregnancy test Will do fine cheap pr expensive.

The ones you buy at the store are basically the same thing they use at the doctors' offices. I don't know the exact time to take one, as some of them detect pregnancy earlier than others. As for me, I used 2 different brand tests, one was the EPT test, which was about 2 days after I realized my period was late, and another (a store brand) a few days later...and they both came back positive. But you should always test in the morning with your first urine stream.

they are usually pretty accurate. Be sure to buy one that is not expired and make sure you wait a day or two after your period is expected, because that way you can make sure your not just late and that gives your body more time to build up that pregnancy hormone. If it comes up negative, than Wait a couple more days before taking another one. If it comes up negative the first time, it's either your still waiting on your period or you still don't have enough of the pregnancy hormone.

They are very accurate specially the branded names like first response. If you test it with your first early morning urine it gets even more accurate.I had done one 5days before my missed period and although the result of the pregnancy in the test was really very light in color but it still gave me the correct result. but it again depends on the hcg levels in your urine. better to get it done on the day of your missed period ( if only u can wait tht long ;-)

in my case not at all. I took four urine tests and one blood and all came back negative at about five weeks even though it turns out I'm pregnant. for most women they usually work a week after the missed period. keyword being usually.

they are take the same time. not very accurate take two if you want to be very accurate.