Implantation or really short cycle?

Stopped Nuvaring a few month ago and my cycles have been 21 days then 23 days then 27 days. This cycle I started spotting day 19. I didn't detect an LH surge so my friend thinks it's just a short cycle and part of me regulating again. I normally spot for up to 48 hours before I bleed but it hasn't happened. Photo was taken when I got a blob of CM. That's also the most blood I've had. 48 hours later there's basically nothing. But was it too red to be implantation?