New to PCOS

My husband and I just met with a fertility doctor last night. Because I used to have very irregular periods (4-5 a year) and because now my cycles vary between 31-38 days he is thinking I have PCOS. My bloodwork came back normal and we are waiting for the ultrasound if I get my period next week. I have of course begun researching PCOS all night. I really need to loose about 20 lbs and I keep reading that will help the PCOS. Has this worked for anyone? Can just 20lbs do that?