diarrhea during 34 weeks pregnant?

So the last time I ate was on saturday , and it was only a burger king chiken sandwich and I left almost half of it and I ate some fries but thats it , then At 4 am I ate some popcorns and then I didn't eat all day , and I just slept and when I woke up I got some donuts , only two and thats it I didn't eat anything else , and then I fell alsep like at 5 pm or 6 pm (yesterday) and I woke up with abdominal pain and feeling really nauseous , but I just ignored it and went to sleep... Today since the morning I've been having horrible diarrhea and abdominal pain when I lay down facing fowards , what can it be ? Or is it normal ? I legit don't have anything in my stomach only two donuts and popcorn and chocolate milk , chocolate milk cause that's the only thing I've consume today.. Thanks for the response