My daughter is 17 yrs old she started her period when she was 11 she has never been regular always skipping a month she was put on birth control to regulate her it did work she then stopped taking them 7 months ago she has not had a period for 3 months i

She needs testing: It's not normal, and she needs an evaluation to determine the hormone imbalance(s) she has. It would be in her best interest to see a board certified reproductive endocrinologist, as this type of specialist has expertise in hormone imbalances in women. If you/she can't find an expert in your area, she's welcome to see me (as women do from the U.S. And other countries).