I too get cramps on the left side of my ribs, op side, if I stretch in certain ways. I haven't had any reconstruction yet.
It does put my mind at rest knowing the problem appears to be common.
I also get chest cramps especially if I stretchin certain directions. I've not had recon but lots of women seem to get these cramps but I don't know when you should start to worry about it or just accept it.
I have had implants, but have had mastectomies and yes for a long time I experiences cramps such as you describe. My surgeries were in 1997 and 1999!! I think for the past year I have had very few. The cramp feels like a vice around my chest going round to the shoulderblade. I don't think you need to be concerned it is just something you get used to, though a nuisance.
I have had masectomy and implant reconsruction. Recon was almost 12 months a go but occasionally when I am sitting and maybe slouch I get a cramp like feeling in my ribs on my recon side and have to change my postition. Does anybody else experience this and do you think I should be concerned.