Have i got a good physique?

Ok, im 17 and 5'11 and i think im pretty skinny, i mean im about 135lbs and have about 10.5 inch arms :( anyway ive started doing chin ups and pressups recently and i can do 5 chin ups in a row and about 40 pressups, i think this is pretty good yet i still have tiny arms compared to people who can do less but have bigger muscles :( any suggestions, should i keep doing chin ups/pull ups every other day or so?