30 Day Shred pain?

so, yesterday I did the Insanity fast & furious workout. today I’m trying level 1 of the 30 day shred (hoping to start the program) but 10 minutes through the video I started experiencing extreme lower stomach pain. like cramps. I stopped and took a 1 minute break with some water and felt better, but the second I got back to doing cardio the pain came back. can someone PLEASE tell me what could be wrong?
ps: I haven’t eaten for 2 hours!