Spitting up and throwing up

Amber
My 6 week old, Wyatt, spits up so often. She's breastfed but she spits up and throws up half of what she eats. My son (formula fed) was the same way. Doctor says as long as she's gaining weight then don't worry about it. But i worry a little and the damage it does to the laundry pile is nuts. 
Anyone else experiencing this?