Fat nugs, Yellow leaves

So I'm week 13 into flowering and I have some large, juicy, icey looking buds. Very beautiful, but 3/4 of the hairs have not turned red yet. My problem is, all of my fan leaves are curling up, turning yellow and brown, and dying. I don't want it to end up effecting my buds. Ive been trimming them off (i know this is a no,no.. but its too late now). I would post a pic of my babies but all I have is a lousy camera phone and you can't really see the nugs up close and personal. I want to know if I should harvest them now or no? The buds look fully developed...around 4 inch thick.. the hairs just aren't all amber in color and I don't want to cut it down too early. help?! also.. it is a Bubblegum strain... don't know if this helps at all? oh, and btw this problem just started about 4 days ago....

I sure wish I could see some pics. I'm growing bubble gum as well.

You should next look at the trichomes and see if they are clear, milky white or turning amber. Do not prepare to chop until they are at least 80% milky with some turning amber. The pistole will dry out and color. You are real close. As for 13 weeks into flowering, I think you are counting the first day you flipped lights to 12/12? Bubble gum seems to be a late sexxer. More than likely you are just now at 9-10 weeks of actual flowering. Almost there!...

I really need help now guys! Almost 75% of all of the leaves have turned completely brown, dried up, and have fallen off. I dont want this to happen to my buds as they are still green, purple and ripe. Still waiting on more hairs to turn red.... about 50% are... is this strain ever going to be ready???? If I cut them down right now what do you think will happen?

also.. almost all of the trichomes are milky white.

OK it's normal to have your fan leafs yellow and die during flowering. 13 weeks is along time to flower so I would bet it's done if not overdone. My fast strains finish in 7 weeks and the longest sativa I've grown was done in 10 and half weeks. So pretty sure your done, get a trich scope, you can't really judge by the hairs that well.

I finally got a camera out to show ya'll what was going wrong. is it time to chop this thing down or what??

Looks like nute burn or bad ph(or both). I think thats about as done as there gonna get, get a second opinion though.