This morning I went in and had my bodyfat checked in a bod pod, and it was 6.9 % and I weighed 173.5 pounds and I am 5'10.5"
all my fights up to this point have been at 170 pounds and I have won all 3, but have always been the smaller fighter. I have been approached before about going down to 155 but was always worried about it because I was so lean at 170. I guess my question is, with my bodyfat % would it be bad for my health to go down to 155?
To make that weight, you'd have to shed some muscle, as your measurement shows that only 12 lbs of your current weight is fat. That means you are potentially losing some muscle to make 170 (though I'm betting you're smart enough to just cut water weight instead).
I think you'd be wiser to bulk up a little and be a stronger 170 lber. It's obviously a more natural weight for you, and would probably have less (if any) adverse impact on your performance.