For the record, I'm fifteen, and as far as how it happened, we were both under the influence of some rather powerful love songs sung by local Pokemon. But we had a talk about it the following day, when we were both a bit more aware of ourselves, and it included the idea that perhaps this was a little quick.

But we were both fine with the idea. I love him, and I have a hard time imagining that this wouldn't happen eventually anyway. Either way, the marriage won't be until far later, if it eases your concerns any.