I think so. The more you weigh the more you are likely to lose. it also depends on what your diet was before you start. the more carbs you had before, the more you will see a huge loss. When i started LL, I already had cut back on carbs so i lost only 4 pounds or so. Still good though. All you can do is know in your heart that you have followed the plan to the letter and that is all you can do. the rest will take care of itself.
I.did cambridge for 2 weeks first, I lost 7lbs first week and 7lbs the next, then switched to s&s after xmas I'd gained 5lbs over xmas by day 9 of s&s I had lost the 5lbs plus another 1,now my losses are around 3lb a week although I didn't properly settle on 100% plan until 2weeks ago!
Unfortunately I've had a few 'first weeks' - slim & save is an amzing tool for losing weight quickly but I haven't mastered eating like a normal person so when I come off it I go back to feasting! Not this time...
Anyway, my first weeks losses have been between 6lb and 11lb. This time I lost 8lb but only 1lb the following week, I can deal with that though as overall 4.5lb a week is still an amazing loss.