If i get pregnant while using birth control (pills) how will i know im pregnant?

Pregnancy unlikely: Using a reliable birth control method correctly all the time, works very well. However, life can surprise you sometimes. If a woman is not getting her birth control pill withdrawal bleeding during the inactive pills, or if she is just worrying about pregnancy rather often, she can do a home urine pregnancy test once in a while. Tests are cheap, very reliable, and sold in stores everywhere.