Bleeding gums

Does anybody know, if bleeding gums (not always, but when I brush or floss my teeth) is a thing to turn to my ob or a dentist? I am 33 weeks and as much as I remember I barley ever had bleeding gums before but now in my third trimester it is there and annoyng me. Basically I don't have any acky teeth, and as of last december, all my teeth were checked and fine. So now I don't know, is it hormonal or dental problem or well, who to turn to ob or a dentist...