Can I join the Marine Corps, then the Coastguard?

I plan to join the Marine Corps right after high school. After I'm done with that, I want to join the Coastguard and become a helicopter pilot. I wanted to know if it is possible the join the Coastguard after, and still be able to fit 4 years of college into it(a requirement to become a helicopter pilot). Yes, I know becoming a helicopter pilot in the Coastguard is extremely difficult so don't try to down me about it.