Hey there, I've experienced strange sensations like this also while lucid, but I've learned to ingore them because once I wake up everything is always normal. One time I could only see out of one eye b/c my other eye hurt so bad I had to close it and didn't want to end my lucid, another time my mouth and bottom gums hurt so bad I thought my botton teeth were going to fall out (but I realized that it was ridiculous so I ignored it and stayed lucid), another time I was in an LD and a whole chunk of my head was missing and it "hurt" like hell and felt really bizarre at the same time. I don't know why weird sensations like this occur, just learn to ignore them, I guess b/c its more like "fake" pain...and realize that once you wake up everything will be normal again.