Twin: One of two children produced in the same pregnancy. Twins can develop from one ovum (egg) or from two ova (eggs). Twins who develop from a single ovum are called monozygotic or identical twins. They have identical genomes. Twins who develop from two ova that are fertilized at the same time are called dizygotic or fraternal twins. They are nonidentical and have different genomes.
Unfortunately, many women have a small amount of this hormone continuously and if the level gets high enough just before a period, you could get a false pregnancy test result. The best time to use a urine test for pregnancy is three to five days after your missed period.
Simply open the test, place the tip under your urine flow, and wait for the recommended amount of time to view the results. A negative result may be false if the test is taken too early in your cycle. False positives are rare and can indicate a defective test. Here are some signs that you should take a pregnancy test.