Hi ladies could you plz tell me what’s going on.

So af was due yesterday (14th). (Cd one for me the day of the actual flow not the spotting) anyways . Last month I spotted on the other one 13 then it turned into af the following day , but that’s how it’s always been for me . So this month was my first month of Letrozole 5mg cd 3-7. I ovulated on cd 13-14. I spotted again on the 13th so I’m like oh shit this is af because the cramps were just like af cramps. I’m still shocked that it didn’t come because I feel nothing now. But then it stopped like an hour later. It was browisnish /pinkish . Then the 14th nothing/bfn. 15th nothing (didn’t test). Could that have been implantation bleeding? I don’t EVER spot before af, i get the flow the exact day I spot.