I’ve had a tiny lump in my armpit which is sore if I press it for 2 years. It was November 2024 that it was there seemingly overnight, but while I was weaning breastfeeding… and by January the following year I was pregnant and though the lump was there I hesitated getting it checked because I didn’t want to do anything that could hurt my baby. 
now I’m weaning the child who was born 2025, and I notice the lump again. I’m wondering if this is kind of normal for breast tissue fluctuating while breastfeeding or if it’s something I should be concerned about. At some point it felt softer but now it’s back to this harder lump, about a tiny pebble size. It’s quite deep and it only hurts if I sort of pinch it.