I'm almost 17 years old, my penis is 4.7 inches long, is this average or small ?

Remember: Try to not get to caught up on size. You're more likely concerned about this rather than others! I know it's easier said than done. There are studies from the UK that suggest that average male penis is 5.5-6.3 inches when erect.

You're just fine: It's a little shorter than average but you will be able to satisfy pretty much any partner that any other guy can. A smaller guy gets harder and has an easier time stimulating her best nerve endings which are in the front. Satisfaction from being gratified orally may be greater. Don't compare yourself with what you see on the internet, and learn to use your whole body to be a great lover.