I'd give the seller the product of the doubt for a week, and then at least contact them again. Many sellers are 1 person operations, and if that seller is being truthful - they may have taken items to the post office and not yet uploaded tracking information.
While another poster is getting thumbs down, I'd agree that 2 weeks is reasonable until filing a complaint with eBay. It's always best to place yourself in the other person's position and keep in mind that just by filing a complaint, you ding their selling reputation pretty hard. Imagine if the seller really is ill. They will recover, you will eventually receive your purchase, but that case against them will burn them for 12 months.
Dont keep emailing him. He said he was sick and cant ship item on time. So accept it. These things happen. Ebay seller are not stores, they are individual people trying to make a little money. Open an item not received if you want to and request to cancel the transaction. Otherwise, just wait for the item.
After a certain time, you can open up a case or dispute on eBay. Under eBay's money protection program, you are guaranteed a refund if the seller scams you. eBay will hunt them down and suspend their account.
Wait for 2 weeks, THEN file for non receipt.
