okay i had sex november 30, i've only missed a sugar pill before that so idk if that could change anything other then that never missed one before i had sex that day. he said he pulled out but idk how to tell if he did. i missed my first pill december 10 and took it the next morning. i got my period when expected and it lasted 7 days like usually but my flow was a lot lighter then usual.. should i be concerned about being pregnant? i'm stressed about it i've also been on antibiotics for the last week so could that have messed with my period flow?