"I need some advice. The baby seems hard in my belly at night and there's…

"I need some advice. The baby seems hard in my belly at night and there's pain in the groin area. It's not strong pain, but it scares me. I had an ultrasound recently, they wrote "uterine muscle spasm" on the report. The doctor didn't say much. Could I get another ultrasound? Has anyone experienced this before? Should I go to the emergency room or call an ambulance?"