big lump in vaginal canal - normal?

My parents aren't the type of people I (18F) can talk to about this (they've never given me The Talk lol), so here goes nothing. I noticed a big lump near kinda the top back part of my vaginal canal. It's not sensitive or anything, just. there. I've never been to a gyno before and don't really want to, but if this is concerning then I will. Am I overreacting? Is this just a normal part of anatomy? I'm a bit worried lol.