I'm really scared, because I've been sticking my finger in my ...?

I've been doing it for a few weeks, and it's been going in about 1 and a half inches deep. Did I hurt anything? Also, today, I stuck my finger in, and I felt this roomy space in my . what is it? I haven't been hurting, and I still don't have my period. Will this affect me from getting my period and having a baby? Plus, Im a teenager, if that helps. Please Help!