okay so I bought this car seat for my son (due august second)

but I got this insert at my baby shower and I took out the head insert it came with and put it in the box. and replaced with this one. well my grandma was cleaning out the clutter and threw the box away with the original insert still inside!!!

and I'm freaking out because my sister said the hospital won't let me take him home in the car seat with the 3rd party accessory, since it didn't come with the seat.. but it says it's been tested and proven safe on the website. I want him to be safe and comfortable is all.