looking at these you probably have around 3 weeks left in the grow, if your pushing for 70 days that is a great plan, the plant will be more than ready at that point.
if i was you i would start a flush when you get to day 60, at that point doing a 10 day flush would get your girl ready for harvest, your tichomes are what you need to watch, and look more at the buds. these are starting to cloud up and the next stage is amber, looks good, and happy soon to be harvest