Strange light pink watering spotting?? NEED ADVICE!

So I'm two days late and was planning to take a test tomorrow. Was pretty certain I may be pregnant because I was experiencing strong symtpoms I've never experienced before (morning naseau and light headedness, cravings, etc). However my husband and I just had sex tonight and when I went to wipe myself I saw this light pink watery very light spotting...at first I was shocked...huh??? My period??? I don't even feel my normal period symptoms?? But then I realized I've never had anything like this..so light pink and so light...it lasted maybe 5 minutes?...should I even test tomorrow?? What is this??