watery discharge and stomach tightening 19 weeks pregnant HELP!

Jessenia • Mommy of 3 girls ❤️
I will be 19 weeks tomorrow. It started lastnight i been having a watery clear to white discharge from my vagina and its still going on this morning and now. I was driving and suddenly started feeling my stomach tightening. It doesnt hurt but it is uncomfortable. Ive been through preterm labor with my first at 23 weeks but i didnt have any problems with my bag. I just full dilated and lost my mucus plug so i dont know what im experiencing now. I have a doctor appointment tomorrow but dont want to wait and it be to late.anyone else have this going on?