My baby is 12 days old and I noticed small rash like bumps on his head is this cradle cap?

It doesn't sound like cradle cap but it could very well be Baby acne. It's usually on the face but can spread to the head back and arms. Cradle cap just looks like flaky yellow skin then you can kinda scrape off with your nail (softly). For cradle cap, I just rubbed in some baby oil (olive oil works too) and used a baby brush to gently rub off the flakes. Then I gave her a bath. I had to do this a couple oftimes before it went away. Baby acne usually goes away on its own and is caused by the left over hormones from your pregnancy.

There is a new cradle cap lotion made by gerber. It works really well. Other than using lotion and a fine comb, when you give her a bath make sure that when you wash her hair you rub her head with a washcloth very well or use a fine tooth comb while she is in the bath. The water will loosen and soften the skin and will help it clear up. Do this once or twice a day until it is gone, but be sure to use baby lotion on her whole body everyday after her bath or all of her skin will dry out. Good luck. Let us know what worked best for you!!