1 day bleeding... implantation?

I had 1 day of medium bleeding three days before AF was due . I thought AF had come early but it stopped after the first day. After that I’ve had light brown discharge very light. Could it have been IB ? I am 4 days past this “bleeding”day and have had BFN . I hope it was IB and that it’s just taking a awhile to show on a pregnancy test. Anyone else go through this with a successful BFP?