I'd get it out of your system now. The bigger you get, the harder it'll be to twist n crack..which annoyed me to no end, but if I twisted, it would feel like I would start to pull a muscle in my stomach. As long as it doesn't hurt your stomach, it's fine. Deff don't get it to crack by someone walking on your back tho
No. My boyfriend pops my back all the time. Your baby has plenty of padding in there.