Amazon tracking says delivered, but I haven't gotten it yet?

Amazon tracking for the product I ordered says delivered / shipped. But I haven't received my product yet. I selected amazon prime's 2 day shipping, but its been 5 days now (not including the weekend). My doorbell never rang for a delivery to my door, and it was not in my mailbox, which had other mail in it, except the product I ordered. I'm pretty sure no one stole it, because no one rang my door for a delivery, and I still received all my mail in the mailbox everyday. What do I do?