About a week ago I was doing reps of deadlift at 335lbs when I felt a pain on the bottom of my right pectoral muscle, like I had been punched, but focused in an area about the size of a coin; this was on the 2nd set, about half way through. I took a mid-set break of about 2min, then finished the set, and 3 more sets afterwards. The sensation was still there, but the pain reduced during the workout.
This was a new sensation, but two days later when I again went to deadlift the situation repeated exactly, the same feeling, the same pain, and I handled it the same way.
The next day I was doing a different routine, and started to feel this area during bench-press. It wasn't painful, just a sensation like there is an air bubble on the bottom of my right pectoral muscle, popping (and not on every rep, only occasionally).
I had a cardio day after this (boxing), and today I was back to deadlift. I reduced weight by 35lbs for my reps (to 300lbs), and felt the sensation of the air bubble, but without the pain on the reduced weight.
Fwiw, 335lbs is my PR for deadlift, I could easily do 5x5 on all exercises in my routine a few weeks ago, then I started my first-ever cut. I reduced carbs to almost nil, but kept protein around 200g; now I have difficulty completing overhead press, and deadlift, but I have kept the weights constant (until today, when I reduced deadlift).
Because I am cutting carbs, I don't want to reduce volume for fear of losing mass, but if this is an injury I won't want to make it more serious than it is; any help is appreciated.