Why is my stomach big under my belly button?

Could I be pregnant or am I just fat?? My belly is distended bit mainly under my belly button not really where my stomach should be..I have a few pregnancy symptoms like tender sore breasts, peeing alot, and being realy tired often but thats it! I usually pms and have sore breast so thats normal. I haven't missed a period, though they have been light, this month I only spotted a bit..so do you think I am just fat or could I be pregnant and not know?