should i have this test

I was wanting some advise about having genetic testing.  My situation is this my mother was dx with breast cancer at 32 my sister(twin) this past June at the age of 30, my grandmother(maternal)in her early 60's.  My sister had the genetic testing and it was confirmed that the brca-2 was neg. and the brca-1 was pos. @ 87%.  Im just really blown away with all this information.  I would like to hear from people who have gone through this and what they choose to do.

I am a 3 year survivor of ovca 3c. I was tested BRCA 1 pos. as well as my sister and 2 of my cousins one of which died of ovarian cancer in 2006.  My mother died of brst at age 36 (1968) both of her sisters also died of breast cancer and one of them had ovca also. My 17 year old daughter also was tested and I am glad to say she was BRCA 1 and 2 neg.  !!