Yes you should definitely see a gynecologist.
You have " secondary amenorrhea" and at six months this needs to be fully investigated.
The link below gives a comprehensive list of possible causes as well as details on a suitable work-up.
Please get back to me if you need to.
WHAT COULD BE CAUSING THE LOSS OF PERIODS AND PAINS IN MY ABDOMAN
There are not so many causes of your absent periods that are associated with pain - but we would need to consider adhesions within the uterus as well as certain types of ovarian disease.