Husband's sister

Carla • 30. Disney lover. 9 years married 😁 Pregnant with #1!
I took 2 tests Saturday morning (12-19-15) and both were negative. Sunday (12-20-15) my husband's sister takes two test and are positive. She has two boys already that I absolutely love. It's not fair. Like why? I am happy for her, really. But I just don't understand it. Why can't I have kids? Like am I being punished? AF arrived this morning. Next month will be nothing but dr appts for me. Something has to be done. Almost 3 years of negatives. Constant let downs and failures.
*sighs*