Any Ideas?

What are the chances?
When i was little, my mums mum died of breast cancer. 2 years ago, my mums sister had a mastectomy and 2 days ago my mum had a mastectomy and reconstruction because of 2 sites of DCIS in one side. A few weeks ago, I spoke to a locum at my GP surgery and was told that as I was under 50 (37) and they were all over 50, I had nothing to worry about. Yesterday, my 30 year old cousin was seen at a breast screening centre and told that she should have memmograms when she is over 35 and by then would have a 1 in 6 chance of getting it.
I tried my GP again after my mums doctor in hospital told her to tell me about the BRCA test and am waiting for him to call back in the morning.
What also worries me is at a 34H, does the shear amount of tissue i have make it more likely?
AM sorry for being so ham fisted about all this and apologise if I’m breaking protocols in politeness in any way. Am so worried about my mum at the moment, she looks so small and ill at the moment. Although she is joking about wanting to get her makeup on!

I really hope your mum is recovering well now, that bit where your parents need you to care for them is always so hard.
My gran and mum both died from breast cancer, diagnosed aged over 50, my aunt was also diagnosed aged over 50 and I argued and argued to get mammogram tested from 35. I got the testing. I think your Gp is wrong, you may not be BRCA positive but it doesn’t mean there’s no family history of a lower risk gene (they can’t test for these yet)
Change your Gp,argue for a referral to a family history clinic at your nearest hospital centre and they’ll give you a better idea and better advice.
From all I know I don’t think your breast size is an issue