Good afternoon all 
Silver - you poor thing, you are obviously very worried about the whole situation, which is very natural of course. A lot of that worry is probably the uncertainty of it all -you can't plan, you can't think, your mind works overtime.
Once you know what the situation is, it actually gets a little easier to deal with, even if it is bad news, - because you'll get a plan.
As a general guide, radiotherapy is very targeted, on the area of the cancer. Chemo is a whole body treatment.
Roughly speaking the likely options are after surgery,
- Cancer is confined to the breast - Radiotherapy (can also make you feel very tired)
- Cancer has spread into the lymph nodes, or you have several tumours in the breast - chemo and radiotherapy.
The lymph nodes are a sort of filter, if the cancer hasn't got into them, it is unlikely to have got out of your breast.
If it has got into them, then based on the huge number of cells around as a cancer grows, it's possible some (even just one) has got into your body, Chemo will kill them before they can form a tumour elsewhere.
If it's spread to the nodes, you will be offered chemo, - you always have a choice of whether you want to accept any treatment, but in those circumstances (and they were my circs.) there is no way I would turn down chemo, it will be strongly advised.
It is so hard when everything is so indeterminate, but ultimately it's a life or death situation, and the choice you have to make to save your life is a leap into the unknown and difficult times.
But that's what this illness does - it f*cks with your life, and somehow you have to deal with that aspect to come out the other side, into what amber very eloquently calls the 'new normal'.
I hope that's helped a bit, and didn't sound preachy (not my intention) I sympathise enormously with you and all our new members going through this horrid early stage. It sucks.
, hand holding, and support always on offer. Rants, anger, tears and fears all listened to and empathised with. I hope we can help 
xx