How to deal with these conflicting feelings?

Ninki
Hi Everyone,
My Partner and I have been TTC since the middle if 2013 (with a little break) we had a miscarriage in August 2013 and since then, no luck. We are getting married at the end of this year. However my Brother just announced that him and his girlfriend are getting married before us, and that they are 14 weeks pregnant. It was not planned. 
I am very happy for them, but at the same time wonder why we have to wait so long for our BFP, and they get pregnant while not even trying. I can't help feeling that it's not fair, but at the same time they are a great couple and will be awesome parents.
I just don't know how to deal with this.