Mucus plug?

Is this part of the mucus plug? This is from when I started seeing this august 4th. I’ve since lost more and the color is changing. Not bloody but more of a yellow tint. I know losing it isn’t normally a big deal but I’ve been having contractions since I was 29 weeks and am currently 33. I had my last daughter at 35 weeks and have been on procardia for the contractions since these contractions started. Anyone have any experience with this? Should I be concerned? I’ve left messages with my OB but haven’t heard anything back.