Assessing my cumulative radiation exposure involving X-Rays, have had a /lot/ and am concerned.

I am an 18 year old male attempting to calculate my cumulative radiation exposure for future medical knowledge. Because of a complacent chiropractor, I have been exposed to numerous impertinent X-Rays for frivolous and unimportant joint issues. Since receiving X-Rays from a chiropractor can expose you to more radiation than with X-Rays from a radiologist, I have included an * next to the X-Rays administered by a chiropractor.

Unknown (2000-2005):
2 Foot X-Rays = 2 mrems
4 Head & Neck X-Rays = 80 mrems * (No shielding worn)

2006:
5 Hip X-Rays (All at once) = 325 mrems * (No shielding worn)
2 Hip X-Rays = 130 mrems
2 Ankle X-Rays = 2 mrems

2007: 3 Chest X-Rays = 45 mrems

2008: 4 Head & Neck X-Rays = 80 mrems

The X-Rays were taken in the United States. I am uncertain if I have estimated the mRem exposure correctly, which is why I would like to know my cumulative radiation exposure, and an assessment on whether or not the levels of radiation that I have incurred thus far in my life might be hazardous to my health. Noting the number of Head & Neck X-Rays I have had, I am also somewhat pensive regarding my thyroid. Is there any reason for concern? Lastly, is it safe for me to have any further X-Rays done in my life? Thanks.