I say it's never too early. The worst they can say is no and you try again next year/semester with a stronger resume! Just be sure to visit your career center at your school to look it over. At our organization, we are often excited to take students who are in a variety of education stages--- freshmen to graduates. Freshmen come in with a great willingness to learn and we have the opportunity to mold their minds to what our industry standards are. Seniors or graduates have extensive knowledge that we can apply to more complex projects. None is better than the other, just different!! Just be open minded and keep trying. Network with your professors and advisors early!