Hey @SundaysChild,
A week is not going to be an issue. At least then you can sort out the possible pregnancy. You need to not worry so much about the mammogram radiation. It's a tiny amount. Much less than a normal old xray which nobody would think twice about going to have a dozen of if needed.
Mammo's and u/s are sometimes not super fantastic at determining what is calcification and what is something else. This is from experience and a ridiculously hard to find tumour that looked like a few sparkly little stars in the background once it was found. There will be a reason for doing the biopsy by mammogram I would imagine. My first core biopsy under u/s missed it and came back as normal. Perhaps they think there is a better chance of getting the right spot that way vs the u/s.
Whichever way you look at it you won't rest until you know for sure what it is. You could always get a second opinion if that would make you feel better. There are plenty of imaging companies around, you will probably have to pay though.
xoxoxoxo
