mucus plug... preterm labor risk

I had my first baby at 33 weeks 5 days, lost my mucus plug at 31 weeks. I'm currently 32 weeks with my second babe, been getting progesterone shots since week 16, and lost my plug at 29 weeks. Braxton hicks are getting worse and more frequent... sometimes more than 3 or 4 an hour, sometimes none for a few hours. I went to L&D; last week for contractions 10 mins apart. my cervix was barely opened (fingertip in the outer os). HOWEVER... I've lost more mucus almost every day... should i be worried? does this just mean my cervix is dilating more?