This might be a little long but I need some input, advise or opinions. Not sure which one would apply to this. I appreciate anyone who took the time to read this and apply.

I've been on birth control for about 2 years now. I take the pill and never missed a day. That is until the first week of December last year. I continued taking the pill everyday after that. A few days after I missed, i started my period. Only like a week after my last one. I figured that one missed pill messed up my cycle. Even tho I'm on the pill my bf and I use condoms for extra protection, most of the time. Some time between the missed pill and christmas, we didn't use a condom but I was still on the pill. After Christmas I felt like I was starting my period again but during the time I should have had it. But it was really light and lasted for like a day. Last week I was feeling different. Different enough to make me think that I might be pregnant. I haven't started my period yet. I took a test last week and it was negative. I'm gonna wait one more week before taking another test. According to my pill card I should start my period next week. I've been having cramps but unusual cramps for my period. And unusual symptoms I've never had before. Like I was constipated which I never am and tire more than usual. Is it possible I could be pregnant from missing that one pill? Or did that one missed pill mess with my body?