3 week old boy has lumps on chest

laynee *

Just noticed my 3 week old boy has hard lumps under both nipples, from what I’ve looked up on google it sounds normal but my first never had them so I just wanted to see if any other mamas have experienced this and know how long it’ll take for them to go down, he’s seeing his dr Monday so I was going to ask then unless it gets red or hot and he gets feverish. So far it doesn’t seem to be bothering him