Missed period, taken pill perfectly

Hi everyone. I’m just a little confused about what’s going on with my body right now and could definitely use some help/advice. I’d like to first start off by saying I take a lot of precaution when it comes to sex. I have been on the pill since January and have taken it perfectly, never missed a pill and always take it right on time. Also, I make my boyfriend use the bathroom every time before we have sex and we always use a condom and he always pulls out. So. Mid September, my boyfriend and I were having sex and right in the middle of it, we both felt it pop. He hadnt finished yet, nor was he close to it, so he took off the condom, cleaned himself up, and put a new one on him that didn’t break. The week after that, I was supposed to get my period but only got a light brown discharge for a few hours. I wasn’t sure if that was my period or not so I stressed out a little. Fast forward this month, we had sex twice (long distance relationship) and the condom didn’t break and he pulled out before he finished. A few days ago, on Sunday, I started having brown discharge and it stayed for 3 days with even a little bit of blood. I wasn’t sure why that was; if it was just withdrawal bleeding bc I barely bled the month before, or if it was me getting my period early. Now, it is Friday, and I still have not gotten my period. The last two months I have been exercising more than I ever have and have been quiet stressed with the start of a new college, so I thought maybe that’s throwing off my cycle. If anyone has any input, I would love to know! I’m a college kid so walking 40 minutes to the nearest CVS and spending money on a pregnancy test isn’t something I’d like to do. I know pregnancy is super unlikely, but I need something to ease my mind. Thanks 😊