indigestion?? (26 weeks)

I ate a spicy sub from Subway (yes--I had the meat heated) and about 2 hours later laid down with my toddler to take a nap. I woke up with stomach cramps and a burning underneath my rib cage and stomach area. I took some tums thinking it was from the spicy sub. After taking the tums I now have diarrhea. Is this indigestion? I'm miserable.