How do you ask a girl to do it?

I thought birth control pills stop the implantation of the egg onto the uterine wall, therefore eliminating the chance of conception. :f6:
Someone correct me if I'm wrong.

A woman can get pregnant while on the pill and certain medications. Antibiotics cancel out the pill for some reason. Any doctor that is competent and knows what they are doing will ask a female if she is on birth control to make sure there are no issues.