Genetic testing??

Hi, my names Sarah and I’m 30 years old with 3 wonderful children and a loving fiancé. When I was 15 I lost my mam to cancer (lung & liver) my auntie (mams sister) had died of cancer 6 months before her. My mam was 45 and her sister was 41, when my mam was 40 she was diagnosed with breast cancer. She had her treatment but dispute being “cancer free” for a few years it returned in 2006 and 8 weeks later she passed away. Her sister was diagnosed with breast cancer in her 30’s and then another type of cancer which she died from. I’m not sure which type but I know with both of them it stemmed from the breast cancer. Now I have a decision to make, do I have the genetics test done or not? I have to go private if I do decide to have it done and it’s €1,200 which is a lot of money when you have 3 small children. I’m not sure if my mam or aunt had the cancer gene so I’m confused if I should have it done. How can they tell if I have the gene if they don’t know if my mother or auntie had it. I don’t have enough information about it and I don’t have anyone to ask advice or talk to that understands. Is it worth getting the rest in your opinion? Maybe my mam and her sister were just unlucky or could they possible have had the gene themselves. Any advice you can give me would be greatly appreciated. I’m a bit lost at the minute. Thank you.