How is the home pregnancy test done?

Follow instructions: Home urine pregnancy test is reliable by 3 weeks after sex (3 weeks after when conception might have been) or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test. If a woman gets her normal regular period, then she is not pregnant. Tests vary a bit, so read the instructions on the box.