Does Norgest Helps To Cure Thickened Endometrium?

My wife missed her period last month and today is the 16th day she hasn t faced her period.when we did a ultrasound it was found that her endrometrium has thickened to 19 mm.we went to a gynecologist and he prescribed a medicine named Norgest for seven days 3 tablets each day.Will it be useful or we have to perform minor operation for it?