I'm not sure of anything but she went from 255G yesterday to 262G today. I am just confused.
are you weighing her at the same time every day?
have you checked you scale for accuracy?
depending on the type of scale, some won't work well if they are not on a totally flat surface (mine is like this, if it wobbles even the teeniest bit, it will give many different wts or, if I'm lucky,just show an error message)
check the batteries, too, if they are low, the scale can be off.
take something you know the wt of, and put it on the scale several times, in several different spots, and at different times and see if it's coming up accurate.
also rats tend not to sit still, so when you weigh her, is she moving around a lot?
you can be getting fluctuating wts just from her movement while on the scale.
I agree with lilspaz, she does not *look* pregnant. I have had baby girls who were never pregnant have rounder bellies than this lady lol