Well, the only difficulty I've had a couple of times was some bruising, I think from doing a bit too hard a suction. If your are experiencing no particular soreness and have no bruising or anything, I would think you're OK. When this has happened, I just stopped suction for a week or so until the bruising goes away. I'm no medical pro, though, so that's just a lay opinion. It certainly wouldn't hurt to mention it to your doctor and as about this if it really concerns you.
What sort of results are getting, BTW?
What sort of results are getting, BTW?