Is female anal masturbation dangerous?

I'm a 16 year old girl, and I like to masturbate anally. Recently, I've seen a lot of things about it being unsafe and about how things can tear and you can get some horrible infections and worse things. I usually use my fingers and I keep my nails trimmed. Going to a shop to get an actual toy is out of the question since I'm two years away from legally being able to do that. I can't get actual lubricant either. I usually use a lot of spit. It feels good, but I'm worried about everything I've been hearing. It would be extremely embarrassing having to go to the hospital for that kind of thing. I never use things that could potentially get stuck. I just want to know more about the risks, and what I can do to be as safe as possible? I don't want any stupid answers saying that it's bad and I'll die if I do it again, so please be mature about this.