Confused....please help

Ok...my period is scheduled to come on in 13 days...it went off last week. My boyfriend and I had sex on Tuesday, my most fertile day. He didn't pull out. Today I had a creamy discharge, which let's me know that my fertility is ending, earlier today while at work. I arrive home at 5pm and go to the restroom because I feel discharge. When I wipe, there is medium spotting, practically like the 1st day of your cycle. What does this mean?