I dont think u should worry, if it was regular flow, then ur fine, sometimes after losing V, your hormones change...i hope.ull be fine. I know how u feel :( so stressing and start thinking way past the future..
Ugh im going throgh the same thing with birthcontrol,it was my first time havig sex he didnt ejaculate and im 4 days late and im freakig out
Your period does not sound like it was abnormal the past month (shorter, yes, but you're not saying barely-there spotting that lasted 1-2 days), so it could be anything from stress to a change in diet/exercise habits, illness, weight gain/loss, hormones, etc. You can test to be sure either way to ease your mind.