Hi my girlfriend and I are sexually active and we're not sure if she's pregnant or not. Her and I rarely have sex and our last time was 22 days ago while she was on her period. She recently got a pink discharge and she gets her period Wednesday. She is on the pill, we use condoms, we chek those condoms, I did not finish inside her, and we did it on her period. What could it be? She also changed birth control pills for this month too so it is a new brand, please let me know thanks.