Which date do I use?

[Avengerhart85]

Hi there...new to mn & got my bfp Monday but I'm a little confused on which day I should count from.
Myself & DP were TTC for last 3 months (on CP before) & I had 1 AF 6 weeks after, 2nd AF (so June) 28 days later...but 3rd AF (July) started 28 days later but browny, then stopped, then red 3 days later then stopped?!
I didn't use OPK so unsure on ovulation date do I count from the brown AF or when it started properly 3 days later?
Sorry if TMI

I would count from brown af, explain to doc or MW and they will decide. You won't really know till dating scan tbh.

Thank you