Looks to me like you have two different strains going there. I've grown sativa dominant strains like Orange Bud that are not ready until almost November. I've grown indica dominant strains that are ready by mid to late September. So we're talking 6 weeks difference. Harvesting a plant 6 weeks early or late can really fuck the potency.
Get yourself a 30x microscope (otherwise known as a "jewler's loop") on ebay on the cheap and start looking at those tricomes. That way you can be sure you don't fuck up. If you've put enough effort into getting the plants this far along, take the time to do it right. That's my advice.
A 100x is even better, so I hear, but I've never used one.