Why does it bother me so much?

I'm the first person in my husbands large family to have twins. Everyone is thrilled for us. We are due next month. His cousin just got pregnant and she did that stupid "ring test" and it said she was having twins, a boy and a girl. She was pregnant two years ago and did that stupid test, and it said she was having a boy (which she did), then a girl next, then twins. So both times it was different. She insists that she is having twins because of that test and since I am why can't she. She literally doesn't even know how far along she is and insists on telling everyone it's two and what is she going to do with two babies? Ugh, I'm just annoyed. Her sister in law got pregnant and did the same thing... Now she has to. I'm irked about it because just stop! Just because I am doesn't mean you are!! Sorry for the rant...