Hi Debs
I know it seems hard to believe right now, because you have the doctor telling you one thing and you read other stuff. But the decision is yours and at some point (it may be a week, or it may be years) you will know what is right for YOU!!!
I was happy to keep my healthy breast for years. I had BC in 2007 and had mastecomy. In 2009 I had a mammogram that showed some spots or something, it turned out to be nothing but at that point I and in that particular moment it became clear to me that I needed my right breast removed for peace of mind.
Now, please don't take this the wrong way, I am not saying you should have your breast off!!! I am saying that you have so much on your plate right now with chemo and then herceptin, but in time you will know what is the right decision for you. Do your research (which you are doing by coming here and asking women with a similar diagnosis), and make an informed decision when the time is right!
I was Grade 3, ER+, Her 2 -, and my Doctor told me the same as you "why remove healthy tissue". As my children are so young, I wanted to do everything in my power to be here as long as i could. When the final curtain draws on my long life, I will be able to say that I did everything possible to be here for as long as I could. Obviously I have lots of lifestyle choices in addition to having my breast removed.
Ask many women and professionals for their opinion and make your choice when you feel the time is right.
Good luck with your decision.
Tanya