Pain in my penis after covering during ejaculation

I'm a 14 year old male. Sometimes I put toilet paper over my penis when I masturbate so it doesn't go everywhere and I have to clean it up. Just so you know, I don't tightly wrap it or anything, I leave about a 2 or 3 inch clearance between the paper and my penis. Today I accidentally did it too close and I had a pain in my penis for the next 15, 20 minutes. It's gone away now, but I googled what happens when you cover your penis and saw things about it entering your bladder and causing an infection, and read somewhere it could even cause infertility. I'm extremely worried and wondering if it will be okay or not. For the record, I've never covered it before and this is completely new. I've read that people have done it for like 8 years and I've only done this once.