We are using a friend's beautiful wood bassinet for the first few months in our bedroom. It is custom made so the mattress isn't the standard bassinet size - we found out it's larger. They provided us with one sheet but we want to get a few more. So we have found changing pad covers would fit the mattress pretty darn well. Any reason we shouldn't be able to safely use a changing pad cover as fitted sheets? Are the fleecey ones ok to sleep on?