I recently delayed my period by 2 days using birth control (I'm already on the pill). I had genuine reasons to do so; I am being treated for a prolonged UTI and the doctor would need to examine me. I thought I'd just get my period 2 days later, but that didn't happen. When I spoke to my gynecologist about a week later (I am now 12 days late!), she told me to take a pregnancy test in 2 weeks' time to rule a pregnancy out. Since I am already on the pill, and my boyfriend and I had penetrative sex only once for the past two months (because of the infection, I can't have sex at the moment) I am worried because we had sex that one time whilst on antibiotics. I have been taking the pill regularly though. I've also been feeling bloated for the past few days, like you would just before your period (or a pregnancy!), and my breasts feel heavy, not sore, but bigger. I'm going nuts because I can't imagine the worst case scenario. So, on a more positive note, is it possible for an entire cycle to change by delaying your pill by just 2 days?