Lower abdomen tightness

This morning I woke up with what I thought was cramps but its like just above where I get my cramps and I know its not constipation but it feels like a tightness just like period cramps and I'm really nervous. My period is due any day but my SO and I also had sex almost five weeks ago. We didn't use protection but he did "pull out" but he "finished" earlier than he wanted to and swears he didn't inside me but I'm still nervous. Does it sound like a sign or am I just paranoid?