Yes. The chance that you could suffer a loss begins with the first day of business. If you suffer a loss and have no insurance or have improper or insufficient coverage, there is very little, if anything, your insurance agent can do to help you. You must be prepared for the risks that are inherent in any business and the losses, sometimes catastrophic, that they can cause.
Also, many states and local jurisdictions require that businesses be insured to begin operating. In addition, if you rent space for your business, your landlord will probably require that you be adequately insured as well.
When was the last time you updated your business insurance policies? Take the Quantum Challenge to see if you need an updated policy. (Short answer: You do.)