I'm 39+3 weeks and for the last couples days I've been having a pain right below my belly button that seems to mostly happen when I'm walking and its on and off. If I sit for a while and get up it stops for a bit but usually starts happening again.. Some times I can feel my stomach tighten when it happens but I don't think they're normal contraction's. I'm a ftm and don't know what's going on..