Vomiting and diarrhea at 37 weeks?

So last night I woke up at like 11:37 and was very nauseous which I have been for a few weeks now my nausea went away and recently came back but I got up twice to throw up and it was violent. I also had diarrhea once yesterday and once the day before. I didn’t have this with my first so I’m not sure what’s going on. I feel fine except when I’m throwing up. I read that your body “cleans it’s self out” before labor. I’m currently 3 cm as of last week and I go to the doctor this Thursday to be checked again. I also found this little tiny thing in my undies yesterday it looked like a white balled up booger sorry tmi. But I guess that was a little piece of my mucus plug? Any one else had these symptoms before labor to?