Hi! My dog's name is Tebow Harvin, and he just turned five months old! He is such a sweet boy and already housebroken...incredibly smart!! Knows how to sit, shake, and lie down

I adopted him from a shelter when he was 9-10 weeks old, and was told that he was a "lab mix." Alot of people tell me that it's obvious he is part pit as well, but I'd like to know what you think! I contemplated DNA testing, not sure if I want to though!
I attached some pics, hope it worked....if not, someone tell me how to tell pics!!
THANK YOU!!