Cycle day 37?????

Kaisia
Today is cycle day 37. I was told it can take a month after implantation to get a positive test. I had my last regular AF on 8/24-8/28 had spotting on and off a week later for 3.5 days now I haven't had a drop of blood since then. I'm a 24-25 day cycle person gotten bfn so far. Anyone have input