any help please? pregnancy

[Georgie]

Hi
I have posted this in newcomers but I am not sure now which is the correct one.

I am new to this site. Last year I was diagnosed with BC. I have had the surgery, chemo, radiotherapy and had just started Herceptin when I found out by a complete surprise I was pregnant. They stopped the herceptin straight away. They have agreed to restart after the baby has been born. I am worried about stopping herceptin. Can anybody help as to whether I am in a dangerous position? Or what position I am in regards a likelyhood of recurrence whilst being pregnant. Any help/advice is appreciated.Thanks

My history is as follows:
breast feeding my second child and found a lump under the arm -
Lumpectomy with no clear margins, then mastectomy L breast.
Biopsy results:
1st tumour 2.5cm (lumpectomy), 3 other tumours collectively amounting to 9.6cm (mastectomy).
All Grade 3, HER2+, ER negative
2 out of 8 nodes positive

Could I just add the following:
I was breast feeding my 8 month old son at the time of diagnosis. I am told that the cancer developed during either pregnancy or breast-feeding of my first born. Which could indicate that pregnancy or lactation had an influence??