Hallow Dear, If you have been tested for Thyroid and reported normal, one differential diagnosis can be omitted. Initially, if you take Progesterone tablets for 5 days and then discontinue, you will get withdrawal bleeding within 4-7 days. You may observe your periods for few months. If they are regular, nothing need be done. However, if the irregularity persists, you may have to undergo the investigations. Delay is period by 2 months with negative pregnancy test is suggesting the possibility of Polycystic Ovarian Syndrome (PCOS) in which the eggs even though matured are not getting released. They are stuck up in the ovary. It is due to many hormonal and metabolic imbalances. Please get your blood examined for FSH, LH, Prolactin, Oestrogen and Progesterone. Also ultrasonography will help to detect PCOS. If it is PCOS, you will have to undergo treatment by hormonal supplementation. There are options of surgical treatment like ovarian drilling also. Apart from PCOS, there could be many other reasons for hormonal imbalance. Please report to your Gynaecologist for precise diagnosis and appropriate treatment.