On average, penis growth begins at age 13 or 14, so you're only now hitting the age where that growth might start. So, this is not cause for concern, and is one of those situations where you'll just have to wait and see what happens.
Penis growth can start anywhere between ages 11 and 16. So, if you've hit 16 or 17 and have noticed absolutely no change yet, then you might want to check in with a healthcare provider to see if there is an underlying issue.