Sleep O's

Archana
My sleep Os are followed by painful uterine cramps. Does this happen to anyone else? Are these crazy-intense pregnancy hormones ? I get really scared that it would hurt my baby.I don't want it but it comes by itself... Not sure what this could be? It hurt so badly and took a while to stop it,the cramps are certainly enough to worry me. It usually just takes a sexual dream or even if i feel like im about to wake up to use the bathroom. It sends me right into an orgasm. The sensation starts then all the sudden goes into cramping like my uterus muscles are cramping up. This is happening alot. I would have never known how frequent they were if it wasn't for the pain waking me up.I'm wondering what causes this?