Abdominal pain

Cheyenne • An Army Guy's Butterfly!
Ok so I just started the first period I've had naturally in three years, (without forcing with progesterone) and I've got this pain any time I used my abdominal muscles, like something is being pressed hard up against my pelvic bone... Is it just that my uterus is swollen? It doesn't feel like cramps, I have those and they are much different. Just curious...