I do exactly the same because I'm left handed too!
During college (I studied design) it drove my teachers crazy until they realised what was going on when checking my sketchbooks. But in the end, they loved it and made sense to them haha Some said it was genius and it became some kind of personal signature.
In practical terms, my hand is cleaner than before and it's quite nice not seeing it full of graphite. It didn't take much time getting used to it because it feels more natural than writing pages right to left.
So, I think that if you already started doing this, I'm sure you will totally get used to draw like this soon; but in the end the decision is totally yours!
PS: It's been years since I do this and now it feels weird to start a sketchbook the "usual way".