Sick/diarrhea

Tara • Married for 5.5 years. Mama to two under two. 15 months apart.
I'm currently 33 weeks and for three days now have had straight diarrhea.   Has anyone else had this? I have no other symptoms.   Just feel a tummy ache then it comes on.   I see the dr next week.  But as a FTM just wondering if anyone else experienced this???