Should I go to the doctor or something?

So, I (m16) noticed while showering and cleaning the back area that there was a strange, quite small lump right in front of the exit. It doesn't hurt in itself, but if you apply slight pressure to it, it's quite uncomfortable. It doesn't bother me when I'm emptying it, but it does bother me a bit when I'm wearing my plug, which is why I haven't done that since. So I wanted to get some other people's opinions.

Thanks to everyone in advance

Best wishes and have a nice Sunday evening