Breast bud or lump

Mckenna

My son is 8 weeks almost and yesterday I noticed a little lump under one of his nipples. Of course I cried before I looked anything up lol and I called his doctor this morning (still waiting for a call back) the nurse said everything sounds ok. When I touch it he isn’t irritated by it he is eating and having wet diapers like normal also. Have any moms had experience with this ?