NBA's Brandon Jennings -- Baby Books Are For Chumps

Sorry Dr. Spock, you will get NO LOVE from NBA star Brandon Jennings ... who says he won't be reading "no damn baby books" while his GF is pregnant.

The Detroit Pistons point guard recently announced that his model girlfriend Tae Heckard is with child -- it'll be Brandon's 3rd kid ... but his 1st with Tae.

Jennings says he's SOLID when it comes to parenting -- he changes diapers, he warms the milk, everything -- which is why he doesn't need another crash course in being a dad.

But when it comes to predicting the sex, Jennings says he's 100% certain this one's a boy -- since he's already got 2.

So, will he ever have a girl? "I don't know. We'll see. If my next baby mama's with it."