2 half sisters BRCA1 possitive

Well now I'm wondering what my chances are of coming up BRCA positive.

Now for the back ground story. One of my nieces, my sister's daughter, was diagnosed 5 months ago with stage 4 breast cancer. She is 44 yrs old. She was tested and is BRCA1 positive. She contacted her half sister, both have same mother. She also tested positive for BRCA1. My mother, their grand mother, had breast cancer at right about age 50. The testing wasn't around when my mom had it. She passed in 1998 so there's no way of knowing.

My father died of lung cancer. My sister, my niece's mom, died of Liver cancer 2 yrs ago. An aunt on my dad's side died of breast cancer. Since both of my nieces are BRCA1 positive but are only half sisters that leads me to believe that the link must be on my side of the family. Do you think that's a reasonable assumption?

So that brings me back to really wondering what my chances are of coming up positive. The blood's been drawn and I had to go back and answer some questions to authorization from the insurance company. I just have a hunch that I won't have it but that could also (and most probably) be hopeful thinking.

Does anyone know how long it might take to get the results?

Anne