My girlfriend and I had unprotected . Could she be pregnant?

My girlfriend and I had unprotected earlier today. She just started on birth control and at the time it had been 72 hours since she had started, taking a pill every day. (P.O.P.S method) We read that after 48 hours pops becomes effective. I did not inside of her; I made sure to pull out. However, I am very afraid that pre *** could make her pregnant, even though I pulled out and she is on birth control. Looking back I wish I didn't do it because now I wouldn't be sketching out. Has anyone else had while on P.O.P.S after only three days? She refuses to take the day after pill because she is sick of taking it. She has taken it twice before since the condoms broke. P.O.P.S is supposed to be 99.9% effective. Does that statistic count after 72 hours? I am very nervous. We are 16 and definitely not ready for kids and we both do not believe in abortion.