Idk if this is the right forum I'll delete if needed

Brandy
Is it wrong for me to be mad that my sister in law announced she was pregnant after only a month of trying? We were headed on a 3 day get away and we got the call that she wanted to tell everyone that she was pregnant. I feel like I should be happy for her, but I'm not. Her husband is a pos that has cheated on her on numerous occasions. I just feel like when will it be my turn?