How long after first bfn did you ovulate?

[Amygdala]

Hi ladies! The question's in the title really. I've just come out the other end of a mmc and we've decided to try again straight away. I should have been 12 weeks and the yolk sac measured that but the embryo only measured 8+4. I had medical management and then bleeding for a week and still have brown spotting 2 weeks on. I got a bfn on Wednesday though. I'm now wondering: does a bfn mean CD1? Can I expect ovulation around 2 weeks later or is it still really variable? How soon after your bfns did you ovulate? Did anyone ovulate less than 2 weeks later? Or a lot more?
I know this is a difficult topic and I appreciate any information you're happy to give me.Lots of very sticky to everyone!