Yes, you may be covered by more than one life insurance policy. In fact, stacking multiple life insurance policies is a good way to add or remove coverage as your life circumstances change.
For example: Once you get married, you may get a $250,000 term policy to replace your income. Once you buy a house and have children, you may opt to pull out another $500,000 policy to cover the loss of income and help pay for the mortgage and additional expenses of raising children.