I started on it at about that age (that was like 10 years ago though, LOL!) - and it was a LIFESAVER! Mine were heavy and super-irregular, so I could never predict when I'd get it. It really was a nightmare.
It took a few months on the pill for me to get straightened out, but after, say, 3-4 months, I had a completely predictable period (I took the last pill Saturday, I knew I would have my period from Tues/Wed. to Friday/Saturday), and it was so much lighter. Never any trouble with leaking, being unprepared, anything. It also took care of a lot of hormonal mood changes, and it totally cleared up my acne (which was mostly hormone related).
The only issue I had is that when I first started, the doctor started me on something like Ortho TriCyclen, just the basic Pill, and when I first took it, it made me violently sick (throwing up). My body just couldn't tolerate the hormones, so my doc switched me to EstroStep, which is a low-dose pill. Sometimes I would be a little queasy the morning after I started a new pack, but it went away. So maybe start with a low-dose to avoid any side effects like that.
I know it's not for all girls, and I certainly didn't treat being on the pill as a teenager as a "license to have unprotected sex". But it was just a lifesaver for me. It definitely hasn't harmed me in any way.
Edited to add: I didn't have a full gyno exam because I wasn't sexually active. But it was a good way to "ease into" seeing a gynecologist so that when I got older, I was comfortable with it.