Pauly D -- I Have a Love Child!

Pauly D's bloodline will live on, because he has a little girl crawling around -- near the Jersey Shore ... TMZ has learned.

Here's what we know ... The mother is 25, born in Jersey but she met Pauly in Vegas last year. We're told they hooked up while he was DJing in Sin City.

The baby is a few months old, living with her mom.

The mom has filed court docs in New Jersey to formally establish paternity, but we've learned Pauly has already taken a DNA test and he's the dad.

Pauly tells TMZ, "I'm proud I'm a father. I am excited to embark on this new part of my life."