Coccyx Pain--a chordoma, or perhaps another type of tumor?

I've had coccyx pain for about four months now. It's mainly on the very tip of the tailbone but it seems to form a dull ache after I sit on it for awhile. Sometimes my lower back also aches. I had an MRI done a few weeks and I'm really freaked out by the results. The orthopedic doctor didn't seem too concerned and suggested that I have an MRI (with contrast) in 6 months. I've done a lot of research on the internet (I know, never good) and I'm worried that this may be the beginning stages of a chordoma, or perhaps another type of tumor. The doctor doesn't seem to think it's necessary to order an MRI with contrast yet and isn't even sure that my pain has anything to do with either cyst/tumor. I find that hard to believe since my pain is essentially exactly where the pain is located. And also, how big can the distal coccyx be? I understand the cyst/tumor is only 4 mm but isn't that large enough to cause pain? He said the only way to remove the cyst/tumor is by removing my whole coccyx and he dooesn't recommend doing that. I'm also really confused by the suggestion that the cyst could be a small bone cyst (which I'm assuming means simple bone cyst) since that seems to make no sense at all based on the location.
Please, any advice/suggestions would be greatly appreciated.

The report:

A tiny 4 mm cyst is identified associated with the distal coccyx segment. This appears to be within the bone and may represent small bone cyst. Cystic nature is difficult to confirm without contrast. No surrounding soft tissue edema is identified. There is normal segmentation alignment suggested of the bony coccyx. There is likely a Tarlov cyst identified at S2 measuring 4 mm.

IMPRESSION:
1. Normal appearance of the sacrum and bony coccyx excpet for a tiny nonspecific cystic structure likely bone cyst measuring 4 mm. This is of uncertain significance. Cystic nature is difficult to determine without contrast. There is no significant surrounding tissue edema to suggest acute trauma

2. No evidence of significant intrapeliv pathology

3. there is likely incidental finding of a Tarlov cyst at S2.