Is this normal?

Sorry if tmi.

I'm 15 weeks.

This is my 3rd pregnancy. My belly was getting pretty big. Yesterday I had 3 episodes of diarrhea. Stomach was cramping pretty bad. Now I don't even look pregnant. And all today I have period like cramping going on. Not unbearable but uncomfortable. I'm just wondering if this is normal ? Could something be wrong? No bleeding. No changes in diet or anything.

Thanks in advance.