Now that I am researching this myself I see that a crack can become a root FRACTURE and will need to be extracted. Some articles say the dentist could have used fiber optic lighting with dye.
Another advice blog suggested a temporary restorative cap would help diagnose the problem and prevent further damage.
My endo mentioned that a cracked tooth won't be seen on xray this soon after it happened. He said take ibuprofen and hopefully it will get better UNLESS its a cracked tooth! BTW- I'm not getting anywhere with the Q-tip test. I did show the endo my instant pain when the surface of that tooth is pressed on. Is it really impossible to diagnose a cracked tooth in some cases or should I go to someone new and ask for the above 2 options?