AF 6 days late, spotting, impossible implantation?!

[lapetitepee]

Hi everyone! Could do with some advice please. Been TTC for 11 months now. My periods are always 28-30 day cycles and always on time. Never in my whole life have I been 'late'. This month however I am now CD36 and no period. Ive had none of my usual menstrual symptoms either. Then today I felt a light cramping (short lived) and assumed AF was about to hit. On inspection I had a very small amount to light browny/red almost watery CM even in consistency ie, no clots, uneven colour tones etc. just 'coloured thick milk' (sorry TMI!!) popped tampon in thinking another duff month. When I went to check 8hrs later the tampon barely had anything on it, a tiny appearance of brownish sticky mucus like the last day of period spotting but that's it. Nothing since. I'm so confused because this doesn't keep with my period 'timing' and I normally bleed bright red and heavy. I've need trying to research implantation and late periods but the info is mixed with some articles saying completely impossible and others disagreeing. All HPTs are -ve. Anyone able to help? Or perhaps had the same??! I'm going crazy!

Thanks guys!
Laura xx