What Causes Pelvic Pain And Bloating After Having A Miscarriage?

I had a positive urine test (Dr's office) 3/28/11. The same day I started spotting and eventually bleeding like a normal period with moderate cramping on day 1 (no medicine necessary). The Dr completed 2 blood tests two days apart to test hcg levels. I was told there was a "slight decrease" in the levels and to expect miscarriage. 34 days later I had what seemed to be another regular period lasting roughly 3 days. I still have constant bloating (since mid-March), pain/pressure in my lower left pelvic area, achy crampiness in my pelvic area that comes and goes (similar to period cramps, but without the intense pain), and pain during sex near the entrance. All of this has been occurring since the beginning of May. I have had roughly 6 negative pregnancy urine tests between the Dr's office and at home. I went to the Dr regarding the pain and they were not able to locate the cause. I am 27, 5'4", 136 lbs, and have great health. I have had abnormal pap smears in the past (1st one was roughly 3 years ago). My mother's history with all 3 of her pregnancies was period-like bleeding every month for the first 3-4 months. No nausea/vomiting. She was told each time she had a miscarriage but went on to carry full term and have 3 healthy babies. Any suggestions on what to do?