Feeling down

Let me start by saying that I understand that there are couples who have been trying much longer than us and I feel for them.

But anyways, Hubby and I have been ttc #1 off and on since we married Dec 2014 and started seriously trying September. We've been checked and told that there's nothing wrong with us that would prevent pregnancy. I have normal cycles and no medical issues. This month AF showed up again and it frustrates me beyond belief.

And THEN

my oldest sister who never wanted kids to begin with up and decides she wants one and BOOM she's pregnant within a month.

Where's my baby?? This is so frustrating.

Anywho, any tips or advice??