lump on boob help

honeybee • •save the bees•reduce/reuse/recycle•BLM•fucktrump•feminism•she/her•do unto others as you want done unto you•
So there's this little bump on my left boob and I don't know what it is, should I be worried? I'm sure it's not a pimple or a bite. It has a little yellow discoloration and there's a lump beneath it