Birth control late period sorry long post

I've been taking Lo Loestrin Fe for about a year and I haven't gotten a period since June 25. There have been a few times where I haven't had one in two months. Back in March I missed a few pills due to mid-terms and then didn't have one until May. That came with really bad back pain and a heavy period. Sometime this summer there was a day I didn't take my pill until night instead of the morning. Other than that I have been taking them mostly around the same time. My bf and I use condoms also but I'm getting paranoid I've got a bun in the oven. On June 9th we started off sex with out a condom but finished with one. I'm the beginning of August I got really sick with back cramps and stomach problems but I think that was just a stomach bug since my sister and mom also had it. On top of that I got a stubborn yeast infection so I was having really bad symptoms. All the pregnancy test said negative. Another thing is I moved out on my own to go to college. My mom thinks my stress is causing my period to be MIA. I have also gained 10 pounds in the last few months. I have been occasionally having cramps, back pain and my breast feel like they have grown like it's going to start but goes away. Is it possible to stop having a period while on BC? Or could I be pregnant?