All things bodyweight

I've been experiencing some pain in my left side of the back. There is a painful sensation between the scapula and the spine, when i try to pull my scapula down (retract), At first i just ignored it but then i just took a quick break of week from pullups and i think it got better but when i started doing pullps again the pain came back. The left scapula feels less mobile when compared to the right one. Also i think i should add this, while doing a pull-up i feel no pain, it's just when i try to pull my scapula down.

Just wanna know if anyone else has suffered from this or is this something serous.