If you were my patient, I would start with an ultrasound to rule out any retained products of conception (membranes or placental tissue left
in the uterus). I would also check some hormone levels including an HCG level,
thyroid panel, prolactin level, and FSH to start with.
Finally, I would also want to do a complete exam and pap smear to check for polyps or other problems in the cervix.