CM question (TMI, no picture)

So I'm at the end of my fertile week and I've been having EWCM as expected. However, yesterday I went to the bathroom and the CM was the consistency of fertile CM however instead of being the color of egg white it was pink. I have never had this sort of discharge before and I'm not sure what could cause it. I am still having EWCM today but it is no longer pink. 
​Any idea what could cause this?