I order lots from overseas, and although it typically takes around 4 weeks, I've seen it range from 2-7 weeks. Only a very few wind up being 6-7 weeks but it's not unheard of (I have two like that I'm waiting for right now.) I would call it more likely than the odds of CP outright losing it.
Generally, if nothing shows on CP's web site for tracking, they will tell you they know / can do nothing about it. I've found in some cases that some items show nothing until the day it's delivered, then suddenly you get processed, in transit, and delivered all appearing as if by magic.
That's not what you wanted to hear, but I've had worse experiences too - several times the tracking number shows as invalid in the tracking sites at both ends... leaving you totally in the dark!
I'd hang in there a little longer in your case.