A clean CT means NOTHING when it comes to TBI. It simply isn't subtle enough to image damage to all those tiny, but vitally important, axons.

Until you've had a neuro-psych test, I don't think you can be sure you don't have a TBI. In fact, it is quite common for brain injury patients to have deficits of which they are not even aware. Ironically, the worst affected patients are often the least aware of their deficits.

Having suffered both a TBI and whiplash, I know that the physical symptoms can overlap. The ultimate source(s) won't have much impact on how they need to be treated.

However, I would still advise you to have your cognitive function evaluated.