Bright red blood

Tania
I had my period CD1-5, with a little bit of brown spotting CD6-7. On CD8 (yesterday), I noticed some bright red blood when I peed in the afternoon, with something that looked like mucus. DH and I had sex that morning, but not sure if that relates to the bleeding. No bleeding after that one time. 
Anyone experienced something like this before? I'm scared to google what it might be. I have a message in to my doctor's office already and am waiting to hear back.