Engagement Ring on right hand???

Hi everyone--I have been lurking here for a while, my bf and I have been shoppoing for an e-ring. 

I am left handed and I have never worn any jewelry on my left hand--no watch, bracelets or rings.   I wear all my jewelry on the right hand, never on the left!!!!  

I''ve always thought that when I get married, I would wear a small band on my left hand, but that is all I could get used to.  I have doubts about whether I could wear a ring with a stone in it on my left hand.  People tell me to wear my e-ring on my left hand until I get married, then change it to my right hand.  In order to do that, I would have to buy the ring in the size for my left hand and then re-size it later, when I get married.  My ring size is much different on the left and the right!!  The problem is that the ring that I want has a pave band, all around, and may not be easy to size. 

Should I:

try to adjust to having a ring on my left hand and wear it that way for good?

wear it on my left, then change the size for my right later? 

get it made for my right hand right from the start and don''t worry that most people wear it on the left.  If  I am more comfortable on the right, I should wear it that way. 

For those who want the details of what the ring may look like: 

I am trying to decide whether to use my grandmother''s stone.  We do not have the exact specs because we have not removed it yet from the old setting.  It''s a round stone.  We''ve been told that it is probably a G color, 1.2-1.25 carats and the cut is an older cut that has less facets than today''s cuts.  It is estimated that if I have it re-polished it will be a VS1.  Right now, because of a chip in the girdle, it would be an SI-1.  This is all estimated because the stone has not been removed from the old setting.  I am considering re-setting it in the Ritani Endless Love setting.  I have not removed it from the setting yet because Ritani insists on seeing it in the original setting.  (So, how would I get it appraised while adhering to Ritani rules?)

The old setting is gorgeous, a traditional setting with a baguette on either side.  Still, I want to re-set the stone.  I''ve been told that I can opt to have the stone re-cut  stone to be more modern but I think that I will pass on that option.  The stone has a lot of sparkle as it is.  I was told that considering the age of it, the cut is phenomenal.  I assume this means that today''s cuts are much better, though.  Still, I really like grandma''s stone and she she always told me to go pick a setting that I  liked.    My bf is willing to buy me something else entirely, or use this stone.

Any input on what I am considering and what to do about being a crazy left handed person??????????????????