I am 35 weeks pregnant and having a pretty severe headache . I have been having SOB after climbing the stairs at home, persistent backache , difficulty walking after sitting for a brief period of time, severe pressure in the vaginal area and also felt as if I was going to pass out earlier at work! Any ideas what is going on? While I was at the doctor Monday they did an ultrasound and stated that the babys head was so far down in my pelvis they couldn t see his face, but they didn t check to see if I had dialated.