It's not too late, send them in now. If you want to be sure you are on the right track, go to the College Center for Academic Support for help. Academic Advisers are there waiting to help you.
Clusters are sets of related courses.
Each Cluster requires at least 12 credits. Most students will complete at least one cluster outside of their major area of study, and many students will complete two clusters. Consult the Cluster Home Page and Search Engine to learn more. Talk to your Faculty Adviser for more information on clusters. There is a great deal of information there and many people just waiting to help.