What Causes Recurring Swelling And Pain After Ankle Twist Injury?

i have twisted my ankle seven weeks back. Swelling and pain reduces when i will take rest on weekends and will come back when i am back to work. I had an x-ray which revealed no ligment tear. I am able to walk longer distances without much discomfort but swelling and slighter pains are worrying. generally what is the duration it will take to recuperate like these ankle twist injuries