Karly, as a buyer, I think there is nothing at all wrong with a few days to a week lead time. The most important thing is to communicate this to your customers, which you obviously are! I have seen really successful, busy shops saying, "please allow 2 weeks for delivery of your unique product". The impression it gives me is that they are such awesome things that everyone wants them, and they need time to be created.
It kind of makes me feel a little more special...thinking that you are working on my order after I make it, instead of just grabbing a pre-made item. Not that there is anything wrong with pre-made items!
I was equally hesitant to increase my processing time, but I have found no drawbacks. I write in my descriptions, "I make my products in small batches, and fill orders as they are made to ensure the utmost freshness, flavor and enduring quality", so people know where I am coming from (if they are interested).