Is it too late for me to pursue dentistry?

I am currently on my second year at the university of Hawaii Manoa, and still have not found a major. dentistry has always captured my interest and seems like an appealing job, by helping people and you get to be your own boss etc. I am thinking of majoring in environmental science, while also doing the neccessary dental requirements. i was just wondering do i still have a chance to compete to become a dentist. or have I burried myself too deep of a hole? and is a GPA of 3.00 enough to become a dentist? please help me, im at the crossroads and need to make up my mind once in for all.