Most Helpful Girl
I'm confused - are you saying you look lighter or heavier than 137?
If you look lighter than that, it may be because you work out often so would have built up muscle mass. Muscles weigh more than fat but end up giving you a toned look so you would look slim but might actually be relatively heavy on the scale.
Plus, if your boobs are big, that would add to your weight so it's not like that extra 5 pounds is on your bum or thighs - it could just be from your breasts.
As for your back curvature issue, I'm not sure if you are asking a question or just stating a fact but if it really bothers you then perhaps see a chiropractor or a doctor.