Is It My Turn Yet?

On my way into the office this morning I ran into one of my pregnant co-workers. I hadn't seen her in a while. She's really showing now. I'd say she's 6 or 7 months along. I guess you could say I am jealous of her. Seeing her was actually very hard. More than anything I just feel this deep sadness. It's very hard to explain. She announced right as I was beginning the TTC process. This was an "unexpected" pregnancy. And even then, when I heard the announcement, I couldn't help feeling like she was taking MY pregnancy. I know that's not true. But she already has a child, plus two other step-sons. Me: I have nothing. I know life isn't "fair". But gosh, why can't I get pregnant? Is there something wrong? I just feel so broken in many ways. I can't live my life right now. I am trying. I joined Curves. I am really starting to diet. I read books. I've doubled up on my Zoloft. And yet....