Our experts say you should go. Read here or select the Is It Safe? article in Week 13 of the I'm Expecting app.
Dental issues are much more common while pregnant, and almost all dental work is safe during pregnancy. Talk to your dentist. I garuntee they've worked with pregnant women before. It's best not to wait till it's an emergency.
My tooth cracked in my 1st trimester from a cavity and the only thing the dentist could do that was approved by my OBGYN was to have it filled with some putty until after the birth. Man did all the food I tasted that week taste horrible!
Talk to your doctor and your dentist. In general it is a better idea to do nothing that allows decay from a tooth to get septic material into your bloodstream when you are pregnant, but if the crack is new, it is not going to be decayed yet (unless, of course, it already had a cavity and that is why it cracked. This happened to me recently with a molar.) Have you seen the dentist during your pregnancy at all?