Feeling blue

I'm 30 yrs old, been trying to get pregnant for 1.5 yrs, I just found out today that my 21 yr old sister accidentally got pregnant. I'm not happy for her, in fact I can't stop crying because I'm so sad, is this wrong of me? I know jealousy is bad but this is all I ever wanted, and I wanted to be the first one to give my mom a grandbaby.