Positive after implantation bleeding?

If you had implantation bleeding or spotting, how soon after did you get you BFP? I am a day late and had pink tinged cm two days before missed period (I have never had this nor spotted before period) also have had a few other symptoms such as very moody and crying a lot, back pain, period like cramps and I normally only start cramping a few hours before AF starts. Tested day of missed period and BFN! :( feeling really discouraged.