Yes, get it checked; if it's broken and not seen to, it may heal a bit, which may mean it needs to be rebroken to set it. Wor Little Un broke her arm when she was little from a fall (honest guv) and we took her to the army medical centre and they said she was fine because she had movement, there was no deformity, and there was very little swelling.
Two days later we returned and they then referred us for an xray and it turned out to be broken, which meant Wor Little Un had to have a general anaesthetic to have it re-broken and set. She wouldn't have needed this had we had an xray sooner.
Regardless of which, twisted ankles are a pain, literally, not just because of the discomfort you're in now, but it just increases your risk of further twisted ankles for the next 6 to 12 months (so I believe). Because the tendons are slightly stretched and out of whack, the signals from your ankle to your brain aren't as accurate as they normally would be (because you've stretched 'em), which means your body won't correct itself like it normally would.
That's what Wor lass reckons anyway.