I'm in a similar boat as you. I haven't had my cycle since the end of January, every type of test has come back negative, but I've felt movement. Having been pregnant once before, I'm positive that I'm pregnant, even if the doctor doesn't want to listen. I agree with the other lady that you need an ultrasound, it's probably the only way to get a real answer. My doctor won't do anything for me unless I get a pos hpt.
good luck!
Have you had an ulrasound? That will determine if there is something (including a baby) growing inside of you. I would have thought a MD would have ordered that by now. Just the reason that you haven't have a cyle for for months would spark concern from a GYN.