back pain and menstrual cramps

Brit1031

I'm 39 weeks as of tomorrow, 1 cm dilated, and as of Friday I lost my plug. Tonight I've been experiencing really uncomfortable lower back pain and menstrual cramping. Last time I called the dr with a question I was made to feel like the most stupid person on the planet so it makes me hesitate to call anyone. Granted the dr I spoke with wasn't my own it was one that was on call and she is not very nice, but I literally went home and cried after I spoke with her. I have my 39 week appt tomorrow but just wondering what this might be.