My period cramps feel exactly like my contractions did when i was in labor i've been told by the hospital twice, when they did ct scans for an unrelated issue, that i had a cyst like structure on my ovary what could be the cause?

Period cramps ?: Painful cramps with menstruation may be caused by heavier bleeding, which produces blood clots. The clots may not pass through the cervix easily, and the uterus will contract more strongly to eject them, causing pain similar to labor. The ovarian cyst should be evaluated by your gyn physician, as some cysts need biopsy to be certain of their constituency.