It does sound like it could indeed be due to you having rickets - I assume you were treated for that already? I don't think it is a "sign" of anything however with your medical history I would certainly go in for an x-ray just in case.

nope it was too late when i found out to treat it. From the outside my tailbone looks normal but i can definitely feel one side has more bone that the other. This cant be skoloisis right?

My tailbone is always sore for no apparent reason, maybe some of us just don't have perfect skeletal structure, lol

Scoliosis is only significantly treated if your backbone is angled severely.

it could just be a genetic defect or leftovers from a past injury. If it is causing you any pain or discomfort, you should go to a doctor for sure!

Scoliosis is a deformity of the upper and mid spine, not deformities of the tailbone.