Fingered me so hard my period started

Omg my SO and I were having fun earlier and he fingered me. Afterwards I felt more wet than before and just dismissed it as hornies. 
Come to find *6 hours later* he was so rough with it that my period started afterwards. Fml
Kinda thankful cuz I was 5 days late and practically praying for it to happen soon but also pissed cuz it apparently couldn't wait until I got home.