Why Does One Get A Grumbling Sensation In The Uterus?

Hi, I'm 39, have two children and am quite healthy if a little overweight, 16 stone, 5'5". I recently thought that i was pregnant as my stomach swelled up twice the size. Not sure what caused this. Swelling gone now, but my uterus is grumbling. Feels like the wind you get with diorhea, but in the cervical area. The grumbling is constantly pulsating, like breathing, it has been going on now for two days. Any ideas?