Has anyone had a chemical pregnancy? Was it painful?

I believe I am having my second chemical pregnancy. I had one 2 years ago that was confirmed by doctors but had no symptoms until I started bleeding. Yesterday, I got a faint positive pregnancy test and this morning when I tested I got an extremely faint line that you can barely see. This is exactly what happened with my last chemical. Last night I did not sleep at all because I was up all night with horrible cramping and back pain. I have no bleeding just tons of menstrual-like pain. I never had this with the first one. Has anyone else ever had this? My doctor is supposed to call me today to discuss things but in the meantime I am freaking out.