Thoughts... Sister in law..

I was debating posting about this but wanted to see what you all think, get yourself some popcorn because this is a long one.

This all begins with my now husband and I. I have known my husband for going on to 5 years. We moved in together in 2017-Jan. Well my older brother started dating a girl from tinder and was 6 months into the relationship when he decided he would propose on Dec. 25, 2017.. My husband had to my brother he was going to ask me then but decided it wasn't that big of a deal. Therefore my husband waited till Jan. 20, 2018 to ask me to marry him one month after my brother had asked his woman. Well we knew we alway wanted a summer wedding so we planned for June 2018.. Y'all when my brothers fiance found out our date (they hadn't set a date at this time) she was so pissed and cried to my brother and her whole family hates me till this day for it. I have always known she was jealous of my brothers and I relationship but have tried to not let it get to me well fast forward. My husband and I have been ttc for 1 year now and I finally got on clomid and finally ovulated the 6th of November and we BD wellllll guyyyss. My brother and his woman did a FaceTime call with all the family on Nov. 7 to tell us they are expecting....... Im happy for them but now the one thing I wanted I don't want no more she is not even a month and has announced to the world. Im just scarred that if I am pregnant that she will think that I did it as a competition. (my family doesn't know of our struggle with ttc) I feel awful and I shouldn't. there is a possibility that I'm not even pregnant and even thought this is all I ever wanted, now I don't. What do you all think? Their baby want planned so we had no idea this was coming any time soon.. I hope the story isn't all over the place, I would add more details but it's to long!. Am I over reacting?