It's taken me 8 weeks but I've lost 7 lbs!!!
depending the on the type of surgery you've had, 1-2 pounds a week is optimal for lapband (or so my surgeon tells me). the point is no matter how slowly you lose it, you're still losing, not gaining. so you're doing great. 15 pounds in three months is completely doable. also remember, with all the walking you're developing some serious calf muscles; muscle weighs more than fat, even as you get into bette shape.