Hi Char,
So sorry to read your post and for what you are going through. It is so difficult to put something like this to the back of your mind pending a scan and result, isn't it? Perhaps the way to TRY to look at this between now and Wednesday is that if would seem, from what you have said, that you have found the lump fairly early. It MAY NOT turn out to be cancer BUT if it is, you have found it, you will get good an prompt medical care if you need it, I am sure, because of your family history and it is better as there is something there to have found it and start dealing with it (whatever IT is) than to be ignorant of its presence.
I really hope that all works out well for you. If this proves to be cancer there WILL be people to help you. Things do fall in place when they have to.
Please try not to worry yourself senseless between now and Wednesday.
Take care.
V