af isn't due until June 22?

Joli

i had my last period May 25.. normal 5day cycle. didn't start opk testing until cd9 and with my clear blue advanced digital test i got a peak on cd 11or so... but i had spotting from cd 15 to cd20 and everything i read online was leading to pregnancy so I'm thinking no way...i took a test yesterday just to see... and yes! a bfp at cd 20?! i must have ovulated early?