Freaking out

I'm 38 weeks pregnant. Just got back from the doctors and I was concerned about an itchy rash on my stomach. She said it could be cholestasis and she wants me to do a blood test in the morning. She told me if I have it that it can cause stillborn births and harm the baby. I'm worried because it takes 3-7 days to get the results back and Monday is a holiday. Has anyone had any experience with this or have been diagnosed with it?