My girlfriend (not on BC) and I had sex on 11/21 and the condom broke. She took Plan B and had 2 heavy periods over the next 3 weeks. Now on 12/14 we had another condom break (5 days after her last period) and took Plan B again. She normally starts her period on the 17th of the month but that was clearly thrown off by the 2 Plan B induced periods prior. Should there be an expected time frame for her next period or are her hormones way off from the pills? Is pregnancy likely after after having 2 heavy periods & a large shot of hormones like this? She doesn't follow an ovulation calendar so she has no idea where she was in her cycle.

***I'm aware frequenting EBC isn't healthy and regular birth control is safer and much more reliable. We've just never had this happen before.***