Cramps/contractions?

I’m having on and off pain in my lower stomach they are not super painful but I am feeling very uncomfortable also I have had a lot of discharge today should I go to the E.R ? I have a appointment tomorrow but idk if I can sleep with all this discomfort this is my 2nd pregnancy and I lost my 1st due to incompetent cervix I am currently 18 weeks and 5 days I haven’t had any bleeding