Being called selfish

I'm a teen mom, had my baby at 15. I cannot even count how many times I've been told I'm selfish for having a child at a young age by grown women who don't even know me. I'm 17 and my child is almost two and I still get the little remark all the time. I just don't understand how I'm so selfish? I literally changed my whole life for him (not that I'm complaining it's 10x better than it was) I do absolutely everything I can for my sweet baby and being told that I'm selfish just because I had a kid young kind of hurts. I try not to let it get to me but sometimes it just does..