Lopez, 37, and fiance Courtney Mazza welcomed the little girl last month on September 11 and he admitted he's still getting used to having the new addition.
He said to OK! magazine: 'I'm still in that shocked, euphoric stage. Finding out the sex of the baby was the best surprise. I did a big betting pool and everyone was excited.
'I thought we were having a girl, and Courtney thought it was a boy.'
Asked if he has any worries about becoming a dad, he said: 'I come from a big, loud Mexican Catholic family. My sister also has three kids, so I'm used to a bunch of babies [being] around.'