You should definitely have this checked out.
A sprained ankle occurs when the ligaments that hold the bones of the ankle and foot together become stretched or torn with an injury
. This leads to pain, inflammation and swelling. If you do not have much pain or swelling this makes the possibility of a sprain less likely, as usually sprains are exquisitely painful and very swollen.
It is of course possible that this is just a minor sprain, but the fact that you feel that your foot is not under good control is concerning. This is because sometimes, rather than just a sprain, you can actually sustain some damage to one of the nerves in the leg through a strong blow such as you describe. Although this damage is usually transient, it can sometimes be more serious.
You should see your primary care doctor
as soon as possible. In addition to confirming whether or not a sprain is present and ruling out that you have a broken bone, they will perform a detailed exam of the nerve and blood supply to the leg, looking for signs of any injury and deciding whether further workup is needed for a possible more serious problem.