Could Irregular Menstruation Be Due To Overweight?

i am 25 years old i got married 4 years before,since that iam tying to concieve..n my periods are alsouation irregular n iam not over weight also but i hav pcos n my doctor has sugessted to take Normoz with combination of (myo-inositol,D-chiro-inositol,chromium,vitamin d3 tablet).and i am taking normoz from 2 months but still no periods also n pregnency test is also -ve.so plz inform me will This tablet will help me to conceive.and can i take duphaston and clomid with normoz please reply..