Welcome, and sorry to hear about your injury. I agree with both of the above posters. I'm not a health care professional, but I wonder whether a good specialist would want an MRI done at this point. In most cases (something like 85%) following an MTBI, MRI results are clear (ie, no evidence of trauma sequelae), but they can be useful in ruling out other issues.

I live in Canada, so this was an easier decision for me (the cost of an MRI and doctor consultations is covered by the state). I recognize that in other countries, cost could be a factor in deciding whether to get one done.