Small Follicles Found In Ovaries. How To Prevent Ovarian Cyst And Will It Lead To Infertility?

My period was late for three months, the Gyn& ob doctor did ultrasound , noticed multiple small follicles in each overy ( follicular cysts ) with thickening of endometrium lining, then I had my period without any medication , heavy bleeding for about 14 days, the doctor recommend duphostan 10 mg from day 16 to 25 of my cycle for three cycles. I am 42 yrs old, medically fit, high FSH varies between 45 to last test was 17 , my concern is how to prevent ovarian cyst ? I am trying to conceive , could this problem causing infertility ? Thank You, Mona O.