If you on CD 13, assuming you have a 28 day cycle, that should be the CM you see before you ovulate. The next day or two, you should have CM that resembles egg whites (hence the name egg white cervial mucus). The egg white CM is a sign of ovulation. If you're trying to get pregnant, then you should BD with your SO the next few days. If you're not trying, then refrain from sex for the next few days.
I seriously doubt your pregnant if your on CD 13, because your wouldn't have had time to ovulate to get pregnant, unless you have very very short cycles. Hope this helps!
at 12:43 AM on Apr. 20, 2009