THis is a question for the OB/Gyn forum.
I have this sort of discharge when I ovulate. I tend to ovulate 7-12 days after the FIRST day of my period, so if my period goes a little longer than usual (about 5 days) that "egg white" discharge seems to come a little quicker. I sometime will spot when I ovulate, but that has lessened as I've gotten older (I'm 36 now).