Holding your legs up after sex

Brenna
So everyone has heard or even tried holding your legs up after sex. To help you get pregnant. If it works or not I'm sure we have all tried it. Well my husband and I had just finished having sex and I held my leg up for about 5 mins before going and cleaning up. But what I was wondering was how long do you need to hold your legs up? Or how long has everyone tried to?