I exclusively pump milk for son. i noticed a gland under my armpit no lump jus feels like a rolling vein or something. is it a lymph node swollen?

Be seen: You need an exact diagnosis to help with the management plan. It is difficult to think that pumping should cause a problem in your axilla. All the best sorting this out.

Probably OK: Most likely this is just normal breast tissue extending up into your armpit - you are noticing it because you are breast feeding and it will not be as noticeable when you stop producing milk. It is worth mentioning to your doctor though just to have it checked

Probably normal: It may be a lymph node or a milk duct. As long as it's not tender or not to the touch, it's not anything to worry about. If it gets bigger or gets responder, then get it checked.

Could be?: It is possible and could be a location for a lymph node. Without a physical exam it's hard for me to say exactly what it is. So glad you are getting that good breast milk for your baby! My other questions would be... Is the lump sore or tender? Is there any redness overlying? Does it move with your finger? Or does it seem to be " fixed" Do you have a family history of breast cancer?