I'm so angry!!!!

Every time I see my doctor she wants to do a pelvic exam on me even after we've seen the heart beat. I just don't want them until I'm closer to giving birth! I don't understand. All my our friends doctors don't do pelvic exams on them till their closer to their due date. I just want to vent. It irritates me so much and she doesn't seem to understand or take me seriously when I tell her please let's just wait till I'm closer to givin birth. My u/s shows everything is fine. What can I do?