Is it normal to feel this way?

We've been trying for a baby now for 2 years and it hurts me every time I hear someone is pregnant, this morning my sister just rang me to say she was pregnant, and I broke down in tears and I can't find it in myself to be happy for her, is this normal, anyone got any advice on how to deal with it and be able to congratulate her without feeling hate anger and upset that she has the baby and not me, or am I being pathetic and selfish? I don't even think I can face her :(

I have a hsg test tomorrow to find out if my tubes are open or not, im terrified they'll be blocked and I'll loose my chance at being pregnant, anyone else feel this way??