I've never had spotting or bleeding around O time either, but this time I think I did.
I had a 2 day bleed I though was AF, then found out I was pg, so thought it might have been implantation, but according to u/s results the bleeding was the same time I concieved, so I've put it down to ovulation bleeding. I don't understand at all, I don't know how I can concieve & bleed at the same time, but apparently I did...

ETA - I had bleed around 13th Jan, got BFP 9th Feb, BT showed I was about 7 or 8 weeks on 13th Feb (if bleed was AF would've only been 4 weeks), u/s showed 8 weeks around a week after BT. Still confusing though, huh...try being me! lol