Welcome to Android Central! Where are all of your contacts saved? You Google account, the local Phone account, a mix of the two, or some other account?
What phone do you have? Not many phones still save contacts to SIM. I agree with tony bag o donuts (who has one of the most awesome usernames on AC )--save your contacts to your Google account. SIM cards have pretty limited contact storage anyway--I think they're limited to around 250 contacts.