Pain Under Shoulder

i dont know how to describe this exactly or how to tell you where the pain is… When I do pulldowns or assisted pullups, I get this pain under my right shoulder… what I mean is that it’s the muscle on the outside (on the right side) of the armpits, or just below that even. right now i dont remember if it’s right outside the armpits (on the right of the armpits ) or right below the outside of the arm pits.

All i know is that i feel a weird stretching feeling and some pain while reaching the bottom and starting to go back up. it’s not that painful but it’s there and it worries me, and it’s only on the right side of my body, doesnt happen on the left.

does anyone know what muscle that is or why this happens or what i could do about it?

thanks

If you mean under your shoulder near you back, then that’s your lat, if it’s nearer to the front then thats probably your pec.

was just looking at an anatomy pic… it’s either in the lat area or the serratus area… not sure, i should pay attention to it more the next time i feel it.

it’s just weird i had done a month and a half of the pulldowns and pullups without this feeling and then it starts, and only on the right… not the kind of pain you feel from working out muscles… more like it’s being stretched too far or a bone is about to be dislocated… dunno how to describe it, should probably pay attention to the pain more too!