HELP ME FIND OUT!

CAN SOMEONE HELP ME FIND OUT WHAT IS THIS THING JUST POP OUT TO MY SKIN.

IT PLACES UNDER MY BICEP, over my armpit.

anyone help me. TIA

CAN SOMEONE HELP ME FIND OUT WHAT IS THIS THING JUST POP OUT TO MY SKIN.

IT PLACES UNDER MY BICEP, over my armpit.

anyone help me. TIA