Uuh... Discharge Issues

I wear panty liners, and well the discharge it collects has gone from a light color to a orangey color? I mean when i wipe, there isn't anything on the tp. I'm also 20+2 preggers. It's only gotten darker in the last two days. I have an ultrasound on Monday but not with my normal obgyn. I have to go to a big city with better machinery b/c my baby boys heart looked a little weird. (not going into full story). Should i mention it to them or call my normal obgyn?