I'm on birth control and I take it at the same time every day and never miss a pill. During my last pill pack I had sex a few times and didn't use any other form of contraception, at the end of the pack I got my period totally normally (same time, same length, same heaviness). However my breasts have been sooo sore this whole month during my current pack and after a quick, scary google search it says that you can have what seems like a totally normal period at the start of a pregnancy especially if you're on the pill. How likely is that? Should I be concerned?