07/07/2011 06:24 pm ET Updated Sep 06, 2011

It's A Baby Girl For Ryan Phillippe and Alexis Knapp

No paternity test needed, Ryan Phillippe was in the delivery room with his ex-girlfriend, Alexis Knapp when she delivered the couple’s first child, a baby girl. Although Knapp discovered her pregnancy after the pair had already split, Phillippe has been by his ex-girlfriend’s side every step of the way.

“Ryan took Alexis to her last doctor’s appointments and was there in the hospital when she gave birth,” an inside source told In Touch.

Knapp gave birth to healthy eight-pound baby Kai on July 1 at Cedars-Sinai Medical Center, making Phillippe a dad of three. The ‘Lincoln Lawyer’ actor has two children – Ava, 11, and Deacon, 7 -- with ex-wife, Reese Witherspoon.

Although Phillippe was not aware at the time of birth, if Kai was, in fact, his biological daughter, Phillippe has since taken a paternity test and is currently waiting on the results.