Day 4 and you're dropping over 1 lb a day. You're gonna do awesome.
It should taper off to 1/2-3/4 a day but don't worry if you stay in 1 spot a few days, then you "whoosh" 3-4lb.
I've had days where I gained about 14lb from water alone over 3-4 days. Then lost 20 lb in a 36hr period.