Contractions 5-7 mins apart

I'm 35w4d been having BH for the last 3 days. I think I lost my mucus plug this morning about an hour or two later I begin having what I thought real contractions. My sister started measuring it and they were coming 5-7 mins apart for 2 hours before going to the doctor he checked me and I'm not dilated at all. But still having contractions and he sent home. Is that normal? Am I suppose to have these and not be dilated? Is labor coming? I'm confused