Sister pregnant...

So... I just found out my sister is pregnant. I'm so excited for her because she was told at a young age (16, she's now 29) she would never be able to have children, and after 3 years actively trying on her own as doctors told her year after year it'll never happen, she's pregnant. Now, As happy as I am for her, I'm stupidly, insanely jealous and a part of me hates her. It was a kick to the face for me because the same day she got her positive, I got my negative.. I'm kind of resenting her for it, and I don't want to feel like that... I want to be completely happy for her and not feel like a monster.