Registry info. On our wedding website

I'm sending out or Save the Dates in a few weeks and I have the generic stuff on there, including our wedding website. My question is, do I activate the registry portion of our website now? Or only when the shower invites get sent out in a few months? I should note that our wedding website won't be on the shower invites, only the list of the 3 stores (along with the other pertinent shower info.) So I'm not sure people will go to our website for the registry stuff ( I have it set up that every registry purchase through our website will make a small donation to the Humane Society. So I prefer anyone who chooses to shop our registry, do it through our wedding website.) So basically, I'm not sure when to tactfully activate our registry on our website.