Carseat Expired After 6 years?

Izzie • Mommy of a boy and three girls 👦👧🏻👶🏻👧🏼
Hello. I bought a car seat 6 years ago and used it with my first child. I am due in August and was wondering if I have to buy a new one or can I use the old one? I didn't find the expiration date on it.