Is it wrong to feel like this

Today after having so many symptoms I got a BFN! I’ve been trying for 4 months now and my fiancées pot smoking step sister announces her pregnancy on Facebook. She doesn’t look after herself and already has another child that spends 90% of the time at my mother in laws house because she doesn’t care to look after him and it has just gotten me so upset am I a terrible person to be upset, angry and jealous. I know I shouldn’t but I can’t help it.