For the past 3 days my ankle has been constantly hurting whenever i walk, i did completely nothing to make it start hurting. there are no bruises on my ankle either. !

Take rest and dont walk on it too much

Please do not get mad if this is too long

it could be this those

Stress Fractures

A stress fracture is a serious injury which requires attention from a podiatrist to stabilize the bone and heal it correctly. Stress fracture symptoms will include soreness in the ankle, swelling, instability, and pain that may radiate through the entire foot. These symptoms will worsen as you put weight on your ankle.

Rheumatoid Arthritis

Although symptoms of RA are similar to those of osteoarthritis, the cause is different. RA is an autoimmune disease which usually starts in the small joints of the extremities. Early symptoms will include pain and stiffness, then swelling and joint deformity as the disease progresses. Generally, these symptoms will be felt not only in the ankle, but many other joints as well.

but you should get some rest too, and to do some research if you have some time
i hope this help, and i hope you feel better soon.