I'd driven to work and around town till the end of both my pregnancies, in both steaming hot summer and freezing cold winter, even to pick my husband before heading to the hospital after I had water broken with my first one. Always fasten your lower seatbelt over your lap instead of laying it on your tummy, and like always, pay attention and drive safely. If you are an experienced driver and have no problem stay concentrate and calm, you should be able to enjoy the mobility of driving in your car with comfort of warm/cool to wherever you need to go with your growing luggage.
Have fun.