Trying not to freak out but I might be preggo..

Joy
Sooo I had a fwb type of situation and while we used condoms, one time he gapped to finish inside me while the condom slipped off unnoticed..it was before my period was scheduled to start but then I had some discharge and four days of very light pink bleeding.. 
I know it's possible that I'm pregnant but ladies my question being is that do I have real reason to be concerned and to take a pregnancy test soon?