If you are worried, I wrapped all three of my kids until they were at least 8 months old, and I still wrap DD2 two thirds of the time now. I give her a chance to sleep without it, but she makes it pretty apparent that she still likes being wrapped. DD1 and DS stopped needing to be wrapped eventually and sleep fine without it now so it will work out okay.

A couple of things - if you are finding your wraps are getting too small, you can use cot sheets to wrap bub up in - saves money on buying more wraps. Also have you tried angel wrapping? If you haven't and are interested, I will PM you the link to the instruction sheet. It is a looser kind of wrap where their arms are up next to their head and they can move them about a bit. I have only been angel wrapping DD2 for about 6 weeks - before that she just wanted her arms wrapped up like she was in a straight jacket and couldn't move. Angel wrapping is a good transitional wrap if you don't already know about it.