Endometrial thickness. At the earliest!

Hi, I have endometrial echo thickness measure of 14mm I started with my periods on 20jun after two months. It went on for 22 dys. My gynaecologist gave me medicine to stop the periods and asked to do Sonograpphy. The sonography shows that the endometrial is thickened. Now my doc has suggested for endometrial biopsy. I want to know it it is required or there is any other alternative as this has happened for the first time. Also if I have to do the biopsy is it fine to do under local anesthesia Please let me know as I am too confused and looking for a second opinion. I don't want to hurry as well as it has happened for first time and was wondering if there is a medication procrss before biopsy Awaiting response at the earliest Thanks