Mucus Plug

I'm 31 weeks 4 days. I just went to the bathroom and think I've lost part of my plug. I'm very worried because same thing happened last year about this time and then a few weeks later I lost my son at 34 weeks stillborn. So right now I am a high risk since losing him so late. Plus a few other things. I am on blood thinning meds to help me keep baby longer as well. Should I go on or call the doctor? Also past few days my labia has been very swollen for no reason.(No sex or sexual arousal)