It's Good that you've had your meeting @SundaysChild - even tho it appears to have raised more questions than answers.
A week's wait is neither 'here nor there' - it is highly unlikely to cause any concern with your ongoing diagnosis or treatment.
When it boils down to it - it is your body - & your choice. Do what is right for you. Get your pregnancy test done (all the best with that!) .... then take things from there.
To get accurately diagnosed, you usually need to have at least one biopsy and ultrasounds (the biopsy is often under an ultrasound) & (sometimes) more mammograms and possibly other scans. Did they explain why they can't do the biopsy under ultrasound (rather than Mammogram), knowing that you weren't too fussed with your previous mammogram?
All the best xx
