misscarriage / test to be run

I misscarried last 2-27-07@ 11wks. no heartbeat,(had D&C) periods started back like clockwork 28days later. misscarried again on 6-5-08 @5wks.no(D&C)(early misscarriage)hormones were back to normal by 6-13-05. i bled for 5days and then spotted here and there and now on 6-22-08 having full blown period! confused it has not been long enough to have a period, but my doc says mark calendar it could be but i may be irregular for a while. How long? what test should he do? i dont want to keep miscarrying!!!!!!!!!!! I am very fertile- fisrt time my husband and i had unprotected sex i was pregnant, he just got home from iraq 1st of may and i was pregnant by the end of may, why wont they take? why does this keep happening? what test could i ask my doctor for? i feel like he is not doing all he could. please any advice will be helpful.

sincerely desperate