Is Ob Gyn and gynecologist the same thing?

Yes, an Ob-Gyn (obstetrician-gynecologist) is a medical Doctor Who specializes in both obstetrics and gynecology. While "gynecologist" refers specifically to a doctor who focuses on women's reproductive health, an Ob-Gyn also provides care related to pregnancy and childbirth. Therefore, while all Ob-Gyns are gynecologists, not all gynecologists are Ob-Gyns.