take it to a doc, it's so vital to take care of yourself (rather be safer than sorry)
it's happened to me before, but it usually just goes away soon by resting it. cracking it doesn't help much, (although you kinda think it would...)
but if it's happened since wed, i think it's a good idea to see a doc. that's a rather long time.

hmm. maybe you could put a warm compress on it? try that? maybe it's relax the muscles and it'll feel a little better.

take care, keep us posted.