SIL is pregnant

My mil called this morning and told my dh that his sister is pregnant. This will be her 3rd child. She has 2 cute little boys about 22 months apart. The oldest is 5 and the youngest 3. When I found out I was so excited but then immediately I got sad. This is very strange to me. I think it's b/c I just got my IUD and I KNOW I can't get pregnant right now. It's just a very strange feeling. Even thought I do NOT want to get pregnant right now and that it would totally KILL my marriage if I did, it's just weird knowing that I can't. And then the question pops into my mind, will I EVER have another baby? I don't know? My dh just doesn't seem fit for any more. I mean, he had a really hard time transitioning with Teagan and still has moments. As for me, I feel lately that I've even been having moments of meltdown. So I know a 3rd at this moment is not good for us but it was just that feeling of will I? that totally got me down. I feel a good victory is that I did get the IUD and we didn't do anything permanent so we were able to keep our options open. I think we'll be able to revisit the possibility again once we get back on our feet financially. IF we ever do have another, we definitely need to have a bigger house. Or maybe I just have to come to peace with the fact that we are a family of four.