I know that there's no way it'll be even close to an exact science. However, my female standard gray I'm 99% confident is pregnant. Since 4/4 her weight has gone from 556g to 706g and her nipples are lengthening considerably. I was wondering if there was a rought estimate on how many kits she may be carrying based on the weight gain. Has 150g seems way too much to be just 1 kit.