unusual abdominal discomfort

I titled my post this because it's not really a cramp, but just discomfort in my stomach. and I'm freaking out because everything online says pregnancy but my boyfriend HAS NEVER CUMMED IN ME AND IM ON BIRTH CONTROL ! is it possible I'm just experiencing this because of some sort of infection? I have been experiencing the discomfort for 3-4 days now but it's not constant. it comes on more when I think about it more! also tonight when me and my bf had sex my lower belly felt sore. what is this??