Clomiphene alone may not be an effective treatment for most women with polycystic ovary syndrome (PCOS) , which is closely linked to obesity. Women with PCOS who are overweight often begin ovulating when they reduce their body mass index (BMI) with diet and exercise. so before trying clomiphene citrate you are adviced to lower your body weight.then you may get a normal ovulation and will get pregnant.

hi hina.
PCOS is the one of the common cause of the primary infertility and obesity is the associated feature with PCOS. other features include male type hair growth on face and body. the drug about which your friend have told you is basically an ovulation induction drug. certain other drugs exists like bromocriptine but there is not guarantee this can help because lots of gynecologist have tried this in clinical practice but don't have gained any significant results.
what you can do is try to loose your weight and before taking any self medication, first consult your gynecologist as there are more concerned with your health then your pregnancy.
thanks
with regards
dr.ishfaq