text: whats a ob/gyn?? my doc told me to go see one because my cycle isnt regular an ob/gyn is a doctor specializing in preganancy and women's reproductive health. it's short for obstetrics-gynecology.  if your cycle isn't regular, your ob-gyn will do a transvaginal ultrasound to see whats going on with your uterus and ovaries. then she/he will recommend treatment.  i went to one when i have irregular periods. my ob-gyn prescribed birth control pills to regularize me period. it's no big deal.