When I drive my car most of the time it will.

It may have a shift solenoid problem. The best thing to do first is to have the trouble codes pulled to see if it is a solenoid. Any Advanace auto or Auto Zone will do this for free. If nothing comes up you may have an internal problem then. It could be the torque converter or the shift pack for overdrive. At that point I would suggest taking it to a transmission shop. Do not take it to a regular repair shop as it takes a lot of experience and knowledge and special tools to work on and diagnose an automatic transmission. You will save money by doing so. Do not go to an AAMCO though as they are overpriced.