OK here is the deal me and my g/f have been dating for 11months and for 6months she has been on birth control,ok so here is the deal the last time we had sex was 2 weeks ago and I know a girl is most fertile 72 hours before she starts her period.Like I said she has been on the pill for 6 months,but she is now 5 days late on her period,I know stress can cause a late period,any thoughts on what I should do,because im stressing right now.