Cramps. Pregnant?

So today I am a week late. Based on ovulation it could be too early for a hpt to pick up pregnancy. I've had negative tests. But I've had cramping. It's kind of like period cramps but more like (TMI) diharea cramps. I can tell it's mostly gas because of the movement in my stomach when the pain subsides. But the cramps only happen when I sit or lay in a certain position for long. But as soon as I move it feels better. My boobs are so swollen I swear my nipples are made of plastic. I'm nauseous and I'm so moody I can't control myself. Is af still coming or could I still possibly be pregnant???