TMI help!

Ladies please help!!! I am 33 weeks pregnant and got the WORST cramps in my stomach ever. (Like I had to poop) so I go to the bathroom and try. Nothing comes out but the cramps continue. I end up throwing up non stop. And now I'm stuck on the toilet with these cramps and I have diarrhea but I can only seem to get anything out when these cramps come every few minutes. This pain literally had me screaming and crying. I've been stuck here for over an hour. Any idea what this is? Just a stomach bug? The pain is too much granted it is not as intense as it was an hour ago.