My kitty is on 3.0 units of insulin, twice a day. I just bought new needles from Shoppers instead of the vet, because it is cheaper. The first picture is her old needle, which is marked up to 40 units... The second picture is one of her new needles, which is obviously way skinnier and it is marked up to 30 units I have U40 insulin. Am I right in thinking that for the equivalent of 3.0 units in a U40 syringe is 7.5 in a U100 syringe? Please help!!!