Pregnant?

So maybe three-four weeks ago I forgot to take my birth control pills, so i got my period a week early. So after my period was up, my birth control was still at the pharmacy getting refilled or whatever, so my boyfriend and I had sex twice that week, WITH a condom both times. That was maybe two weeks ago, now Im back on the pill since its been refilled. But my nipples have been super sore and tender. Like they hurt to squeeze them like at all, and sometimes my shirt rubbing on them hurts. I read that could be a sign of pregnancy, but also it can be a side effect of the birth conrtol. But ive never had previous symptoms. Help