Is there any law that if I m working in callcenter 4 usa mortgage & i can't work in any other company 4 same

I am currently working in an international call center for usa mortgage as part time ( evening 5.30 pm to 9.30 pm) and I join other company and i am working there same for usa mortgage but in morning 5 am to 9 am.So is there any law that i can't work at two differnt place for same type of work....plz.. heply and reply soon...Ahmedabad,Gujarat,India