Sound like you are doing everything as you should and everything is honky dory. Generally if you are doing everything as you have been any ill feelings are a sign of detox. The wisdom is never end on a low and fast through those tough moments to allow the system to get rid of the toxins it was trying to expel.

Don't put any stock on the pink tongue thing. While there may be a smidge validity to it. After more than a dozen 40 dayers and years of participating on this forum because of the huge variety of results and the fact that most folks won't get the pink tongue at all it's best to just ignore it. So just press on and fudgetabouit.

The weight issue is completely irrelevant as it relates to the MC since what you gain or put back on totally and completely hinges on what you do AFTER the MC. If you do get a little underweight and if you do what you are supposed to do and follow up with a lifestyle/diet change that includes "balanced" and nutritionally dense foods and regular exercise the body will even out and put on or keep off to it's heathiest weight. If you don't change your lifestyle/diet, while cleansing your system is always beneficial it is kind of a wasted effort as you will return to your previous condition or worse as it pretains to weight since you can put on more weight than you lost in a very very short time because of the slowed metabolism which is part of all fasts.