I had sex with my girl and the condom ripped, a week and a half after period may or may not have came inside her should i worry she took plan b?

Possible: Anytime you have unprotected sex, there is a possibility of pregnancy. People are not as predictable as we might like and both sperm and egg have been known to be viable longer than expected. Always use condoms for std protection and another effective birth control method when you have sex, if being a parent is not something you want at this time!