Hi do you think it's really small in size? Also your friends or someone other comment same? Do you have some other physical problem or difficulty? If so then you should visit a endocrinologist. If no and and it's only your perception then you can visit a psychiatrist. Sometime people remain excessive preoccupied with there body appears even after things are well there is no physical problem or other hormonal imbalance. In such conditions psychiatrist will help you.