Students accepted for fall admission are supposed to have until May 1 to decide between the colleges that accepted them (unless you were admitted under a binding early decision program). If your acceptance letter from any college implies that waiting to commit until then might cause you to miss out on housing, financial aid, or any other benefit, please read this past post.
If a college is pressuring you to commit before May 1, consider submitting this confidential complaint form to the National Association for College Admissions Counseling. Pressure to commit is dirty pool and not something that a responsible college is supposed to do.