today is ovulation day

I ovulated April 4th, Af was due April 18th, April 16th I had a tiny bit of pink spotting and the next day I started having really bad cramps on my left side and dark brown dicharge( t.m.i.) only when I wiped nothing ever on pad or pantyliner...this kept up for 3 days.... every test I took bfn....i had a blood test done and they said my hcg levels were undetectable and this was just my period.....so today is O-day again, been getting really busy, hopefully this will be the time. is anyone on the same cycle as me..