Dealing with other people’s pregnancy

Although I haven’t been trying for long (3 months or so) it’s been very hard to hear of other people’s pregnancy. A friend just got off birth control and got pregnant the first month. I literally cried hearing the news rather than be happy for her. Which made me feel guilty, but we have been talking about pregnancy together since I’ve started trying. I seriously want to be happy for her but I’m having such a hard time. My brain has come up with a million reasons why it’s happened to her and not me. I need some advice! I can’t seem to stop myself from thinking negatively (and crying lol)