I also vote yeast infection. And apparently the symptoms can be different when you are pregnant making things more confusing. I was having painful intercourse for weeks and finally told my doc...No other symptoms. He said treat it like a yeast infection and sure enough I am cured now.
Well you could've developed a yeast infection since 27 weeks and now..and yellow discharge is usually a big sign of yeast infection, especially with the chunky consistency.
Weird discharge is generally normal during pregnancy - some odd stuff will come out of your vagina! BUT if you are truly concerned please ask your doctor. It's much better safe than sorry, and you don't want to be stressing out about it if it's nothing.
It really does sound like you've developed a yeast infection and it's very easily treated, so when you see your doctor monday make sure and mention it.
If your discharge becomes green, blood-tinged, or you feel water gushing from your vagina don't wait until monday - get seen at urgent care or the ER. but as long as the mucus stays yellowish and doesn't begin to smell or cause you pain, you can probably wait until monday without any problems.
Relax mama...breathe :-).