can a company force you to work past your scheduled time?

Yes. There is no federal regulation regarding forced overtime. Employees over the age of 16 who refuse to work forced overtime are subject to discipline up to and including being fired. Bills are being considered regarding overtime in the medical field. Employees with disabilities may get special consideration if mandatory overtime is difficult because of their disability, but in general, if your boss says you have to work overtime you don't have much choice.