Not sure if this is the right group but...

I'm not supposed to get my period for another week and two days ago it just pops up. Only its way lighter than normal and I'm spotting today(discharge with a little blood). I had unprotected sex twice 5 days ago today(SO pulled out), am I freaking out over nothing or do I need to take a test? I'm normally pretty heavy and last 4-7 days. I apologize if this is TMI.