Ohk well I just turned fifteen and I haven't hit puberty yet...... I have hair under my arms and some around my penis.... But when I have a erection I'm only 3 inches.... People make fun of me and I need to know is something wrong with my body?
You are well into puberty your pubic hair and armpit hair confirms that.
If you search for the Tanner puberty scale and do the quiz it will tell you what stage you are in along with give you information on growth and development.
You are a long way from being done growing so you could still see your size increase by how much or how long it will take is hard to say as everyone grows and develops at different rates and times.
If you are overweight that can also make your penis appear to by smaller but as people come in all sizes the same is true about the penis.
There is no need to panic you may just have not reached the point in puberty where your testicles and penis grow. That doesn’t help with the frustration or being made fun of but remember you still have lots of time to grow and develop ahead of you.