Hi, I am 30 years old and trying to have a baby for the past one year. I had gone through the follicular study and as on 12th day, the Rt follicle is 18*16mm and left follicle is 7 *6mm, ET is 7.3 mm, and POD is clear. I was given HCUOG 5000 units injection on 12th day and was advised to be with my partner on 13 and 14 th days. Recently, on 18th day, I am feeling period like cramps and lot of tiredness and fatigue. What could be the reason. Please advice.