Pain/aches around my knee area and rib. scared i might have bone cancer! what are my chances of getting any type of cancer?

Stop worrying: Cancer is an uncommon illness especially in the younger years(< 50 years of age). So you should wait to worry! aches and pains like what you have, are common. Unless these get progressively worse, i would not worry but shift your attention to a more active life style like daily walks which will strengthen your muscles and joints . This might give you more energy and a positive attitude too.