at what age did you first give your child a pillow to sleep with?

im just curious. i know there is a risk of cot death in young infants with pillows. but my son is almost 14 months old and can crawl stand and is well able to move. during the day i put him to sleep in a playpen/travel cot and it has a pillow in it and he sleeps so well. but at the same time i am always there in the same room as him while he is sleeping with the pillow. i want to know how long i have to wait before i can out one in his cot?? thanks in advance:)