I had weaned down so I didn't get it, but I've seen a few exampled of delayed carb flu on the forums. Five days may not be long enough yet. You may have had a lot of glycogen and carbs stored up and you're body is still feeding off those. When it finally runs out and is forced to learn to use the fat, that's when it hits.
5'0" female, 42 years old. Started Primal October 31, 2011, at a skinny fat 111.5 lbs. Low weight: 99.5 lb on a fast. Current weight: 109 lbs because of travel.
MY PRIMAL: I (try to) follow by-the-book primal as advocated by Mark Sisson, except for whey powder and a bit of cream. I aim for 80-90 g carb/day and advocate a two-month strict adjustment for newbies. But everybody is different and other need to tweak Primal to their own needs.