Hi my girlfriend n i hve hd sex n during, i noticed the condo broke.i'm not sure now.her period started th day after.can she get pregnant?i'm not sur

Always possible: Any time there is contact of semen to a woman's genital vault, there is the possibility of pregnancy. It doesn't sound like it's very likely in this situation, but you won't get a "no, it's not possible" here. If she misses her next period, she can do a home pregnancy test 1 week after.

Period after sex: Condoms do break. This is a very common scenario. Some will stop the intercourse and replace the condom. But, if your girlfriend's period was scheduled to start and is of a normal intensity and length then she is most likely not pregnant.