Swelling after surgery is normal. Within the first few days after surgery swelling can occur locally around the wound, but slowly this will lower towards the knee (on average after 5 days) and then further to the lower leg until it goes away completely (on average after 14 days). Raising the foot end of the bed the first days after surgery can help reduce swelling. Movability of the leg is still fine, it will only feel more sore.
If there is only swelling around the calf muscle in combination with pain, it is best to contact your GP in order to rule out thromboflebitis.