Hello i woke up this morning and was stretching i reached towards my right armpit and felt a little painless lump underneath my skin. ?

Lymph nodes?: This is most likely a normal lymph node. If it becomes tender or it is increasing in size I would see your doctor. If it moves around easily under the skin it probably a lymph node. If it seems to be stuck down and immobile this would be more concerning for a malignant process.

Probably: a plugged sweat gland...(sebaceous cyst) thatt is the MOST common but other possibilities exist..get it checked out by your Primary Care Provider! Hope this helps DrZ