More/different discharge than usual?

I'm 12 years old, and I've had discharge since I was about 8 or 9 years old. I haven't gotten my period yet, but in the last three or four months I've noticed a change in my discharge. It's now thick-ish and white, and also clear. And in the last few months, most days, I can actually feel it coming out; that didn't happen before. Today while I was playing volleyball, I swear I could feel it, and I felt like I peed my pants a bit (which has happened before). I've read that about 6 months or so before you get your first period, you may notice more discharge than usual.