It's not necessarily too late, but it's flat out ridiculously too early.
It's really silly for someone to do 3 races and then start publicly announcing their desire to be a pro.
Imagine this in other sports:
Do three little league games and start talking about the MLB? Join a high school football team and start talking about the draft after three games? Jump in a rec. league and start talking about posting up in the NBA?
Doesn't that sound really silly? Professional cycling is not different in the ability levels to become a professional.