Hi i had sex1day after her mens.. im worried if there might be some semen leakage from base.since her last cycle was 20 days is there any chance preg?

Maybe. Maybe not.: If a woman gets her next normal regular period, then she is not pregnant. Otherwise, a home 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 period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon and lead to a repeat test.