Hi Slowly. I'm not the expert, but will throw in a couple of observations. If this is your second week, unless you were already on a regular exercise program, you shouldn't be exercising yet. If you WERE already on a regular exercise program, you should have cut the exercise by half for the first three weeks the gradually build up to no more than 45 mins of exercise per day. This program is LOW calorie, and if you burn too many calories with exercise, you enter starvation mode, causing the pounds to be stubborn and hold on for dear life.
Also, The extra fiber may be adding extra calories and carbs I'm not sure what brand or type of fiber you are adding to your shake, so I can't be sure.
Also, if you have less weight to lose, you will lose more slowly. If you only have 35 pounds to lose 3.5 pounds per week (your average loss) is 10%, whereas someone (like me) with 100+ pounds to lose, could expect to see as much as 10lbs loss the first week.
I hope that helps a little
Welcome to the group!!!!