Obstetrician Leonie says: Sometimes it takes three to six months for periods to return to normal after coming off the Pill. However, if they haven't returned after six months, there's likely to be a medical reason, and it usually means ovulation isn't taking place.
Stress, excessive exercise and being underweight are all common causes. Polycystic ovary syndrome, an overactive or underactive thyroid gland, or side-effects of medication may also be responsible.
It's important to see your GP for a check-up so that any necessary treatment can be recommended.