I am not really sure... do i need to lose weight? If so, tell me how please.?

i am 12 years old, and i dont know if im overweight or not.. i do an average of 100- 150 situps a day 50 after every meal and occasionally more. I'm not really sure.. i weigh from 100-110 pounds and i have an untoned stomach and ugly sides.. i eat remotely healthy.. what sshould ido? (Oh and by the way.. im only 4"9)