Welcome although this is one place none of us want to be, but it is the loveliest of forums, with loads of wonderful ladies who help and support each other. I remember when I first posted back in November last year I held off for several weeks from doing it as I never post on forums, but this one has been a god send to me.
You are obviously very worried because of your experience already with cancer in your family. One thing especially at your age, is that it is very unlikely to be cancer, there are a lot of breast conditions which are benign. It is very good that your GP is referring you to have this checked out so that you can get peace of mind.
This time of waiting is the pits, and we can all relate to that, but what you have to keep in mind there are a lot of breast conditions which are NOT cancer. Try and do stuff to keep your mind occupied. You will have the strength to get through the next few days, especially as you have your wonderful mum beside you.
Just keep coming on here as you need and there will always be someone who can help and support you
Sending you a hug