should I call my doctor?!

Overnight I got woken up 2 to 3 times because of horrible back pain and the last time I woke up it was so bad.. I went to the bathroom and noticed I lost my mucus plug ! I've been loosing more and more all morning and having lots of pain in my abdomen and back. I know it doesn't mean labor is going to start right away after loosing your plug but is it normal to having this pain while loosing it ? I'm 38w2 days