Do it regularly and it will make a difference but unless you do loads it's unlikley it wil b eobvious to the casual observer.
Just build it up - tryt o do a few more each day
the problem is that your body weight is too low to have any effect on chest growth beyond the initial spurt. You need to get into the Gym and do some bench presses among other things. Also you need to eat a lot of protein. It's a huge subject, take some advice from one of the instructors in a gym but if you can do 100s of press ups you are getting very little muscle growth.
Push ups alone won't make a lot of difference and too many aren't good for the muscles. It's meant to be about high weights with low reps to gain muscle mass