Why are my legs and feet swollen? Should I go to the hospital if the swelling doesn't go away?

Swollen. See your family doc unless as stated in the other answer there are mitigating factors.
If . If you are not having chest pain, shortness of breath, calf pain and lower extremities that are also red and hot, then you may be fine with just giving your doctor a call or making an office visit. If any of the above are present, a trip to the er is in order. Best of luck.