How many days after sex should i check a pregnancy test ? i'm on depo so i don't get periods anymore so i really don't know when my expected period ?

3 weeks: A urine pregnancy test, done correctly, gives a reliable result 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a regular period (in women who have regular periods). 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.