do you live in europe? Lacking info to answer your question... depends on how far away and if it needs to go through customs, etc. Sometimes takes 2 days from the time you order for it to be sent out, too. Some places are more professional than others. So, it's a bit too early to panic.
I would venture to assume you should be able to get a tracking number at this point. If you are in the USA, sign up for Informed Delivery through USPS. Anything coming to your address will be listed, even if it's from a euro post office without free tracking -- This may not show up for several days after it is initially picked up. If not in the USA, check your local post's website for a similar feature...
definitely stick to established businesses in future.