In need of help!!!!

Ashley
I just had a baby five weeks ago and on the 15th and 16th had unprotected sex with my SO my bleeding from giving birth ended around the third week my baby is now five weeks and now I'm having mucus discharge and don't remember the doc telling me that I could be very fertile after giving birth I go to the doc on the 26 for my 6 week postpartum checkup and was wondering if I am pregnant again would it be to early to tell or could I take a pregnancy test before then?