The presence of any unwanted cyst in the ovary can also avoid pregnancy. Consult a doctor and check it. And also take medications for regular menstrual cycle.
Hi!
It sounds to me as though you may have polycystic ovary syndrome. This is very common and gets worse with weight gain. Basically it boils down to an imbalance in hormones. The hormone imbalance results in infrequent ovulation which then results in infrequent periods. It can be difficult to get pregnant with PCOS, BUT one should not count on PCOS to prevent pregnancy--its definitely not birth control!
The usual treatment for women who do not currently want pregnancy is oral contraceptive pills. These regulate your periods an prevent endometrial cancer.
If you DO want a baby, you may need to consult a reproductive endocrinologist for some fertility medications.
Good luck!
Dr B