No period for last 3 months. feel like i'm going to start & don't. been to gyn, blood wk and ultrasound normal. still worried? what could be wrong?

Many possibilities:: The hormones that control your menses can be affected by numerous factors and result in Amenorrhea: Stress,Poor nutrition, Depression, Certain drugs, Extreme weight loss,Over-exercising, Ongoing illness, Sudden weight gain or being very overweight (obesity), Hormonal imbalance due to polycystic ovarian syndrome (PCOS),Thyroid gland disorders,Tumors on the ovaries or brain.http://cle.clinic/1pxLG2B