Contractions after exercise?

So I was just working out about 20 minutes ago and I stopped due to a sudden sharp pain in my abdomen. Next thing I know my whole abdomen is tightening up and it hurt to stand or sit so I'm having to lay on my left side. The pain and tightness is coming and going every couple of minutes. I called my doctor but am waiting on a call back so I have no answers yet. Has anyone else experienced this? I'm a FTM and have no idea what contractions feel like so does this sound like contractions?