Can a baby sucking on your finger trigger a let down? My son is sleeping in his car seat and I'm…

Can a baby sucking on your finger trigger a let down? My son is sleeping in his car seat and I'm sitting in back with him. He won't take a bottle of expressed milk yet since it's only been two hours. But he woke up for a few seconds and was lightly sucking on my finger. He will probably go another hour before he's hungry enough to eat.