Had sex and now feel contractions

I lost my pregnancy packet.. I am 29 weeks and some change but I just want to know what I am supposed to get concerned about. My last pregnancy i would get braxon hicks but never feel anything but tightening.. with these i feel what a contraction feels like. It comes and then fade and then comes back. Nothing too painful just mild aches. When I had my first it was the same feeling the day I went in to get induced