The only way you can compare how long it'll take to grow your Blue Widow to some elses(like mine), is if you are growing under the exact same conditions boss.
You wanna watch your trichs. I harvested mine about a week sooner than I should have honestly.
But I've 3 different kinds of lighting going on in my space, and the minority of that is CFL lighting.
When you're growing with CFLs, it's always gonna take a little longer because the lack the intensity of HID and T5 lighting.
I would said wait until you think it's ready to pull, and then give it about 4-5 more days just to be sure.
From the looks of that pic, I'd say you should be looking at a few more weeks minimum bro. Maybe even another month