The sensitivity of a pregnancy test is described on the packaging as m IU/ml (milli-international unit per millilitre).In general, pregnancy tests range in sensitivity from 10m IU/ml to 40 ml U/ml.A home pregnancy test is a quick and easy way for a woman to find out if she might be expecting.The do-it-yourself kits sold at drug stores and supermarkets check a woman's urine and can detect a pregnancy in its early weeks not long after she misses her period.If you get a faint, is-that-what-I-think-it-is positive, chances are you're indeed pregnant. Watch the video to get tips on which at-home test is right for you! It may be more sensitive for early testing because it detects two types of h CG, hormones your body starts producing shortly after you've conceived.When it says you can test: 4 days before your expected period How to take it: Your wait time is 3 minutes.If you're thinking about buying a home pregnancy test, we did the legwork for you.Keep clicking to find out how to use the most popular home pregnancy tests on the market. You can take most home pregnancy tests three to four days before your missed period -- but if you test too early, you're more likely to get a false negative, where the test says you're not pregnant but you really are, says Laurence Cole, MD, professor of obstetrics and gynecology and chief of women's health research at the University of New Mexico in Albuquerque.
Some kits have a urine collection cup and a dipstick that you dip in urine.They involved getting a urine sample from the woman, injecting it into a rabbit, frog or female mouse, and then examining the animal's reproductive system to measure human chorionic gonadotropin (h CG) levels, a hormone found only in pregnant women.The first home test kits were approved by the FDA and widely marketed in the United States in the late 1970s.Within 9 days after fertilization , the egg moves down the fallopian tube into the uterus and attaches (implants) to the wall of the uterus.When the fertilized egg implants, the placenta starts to develop and begins to release h CG into the woman's blood. In the first few weeks of pregnancy, the amount of h CG in the urine gets higher very quickly-it doubles every 2 to 3 days. The first urine of the morning (that has collected in the bladder overnight) is the best one to use and has the most accurate test results.