Blood after sex....?

Okay so I’m on my fertile week now today (111/27/17) is day 2 as said by glow. I normally say my fertile week is 7 days instead of 5 because I don’t truly know for sure since every month it changes. Anyways, my husband had sex like 30min ago and when I went to go pee to flush myself out (sorry if that was tmi) because we don’t use protection since we are trying for a baby. I had some red blood come out with it. It wasn’t old blood because that’s normally brown and normally sticky from being old but I’ve been off my period now for a few days! I think the last day of my period was the 21st. What could this be?