Implantation bleeding? (TMI) Yes, I know it's rare.

On Cycle day 19 I had a 22% chance of pregnancy. My husband and I had unprotected sex. Several hours later when I went to the bathroom and wiped, there was just a little bit of super super light redish pink blood. Later on we had sex again and (tmi) the cum was tinted faintly pink. After that, nothing. Now I'm super lethargic. Not tired per se, but lethargic. In a strangely pleasant way.