Hubby's sister (long)

So today I found out from my SO that my sister in law is ttc for baby #3, they're not financially ok and they had to move back with my in laws because her husband lost his job about a month ago. Later after I found out, I went to my in laws and she was on the couch saying she felt really nauseous and started telling me all these other symptoms she's had. I asked her if she was pregnant and she just said she didn't know but she's hoping she is. My husband and I have been TTC for baby #1 for over three years and still nothing. She's one of the few people we decided to tell about this when we had been TTC for a year. I'm so hurt that she might be pregnant and shes telling me not taking into consideration how we would feel about it. Don't get me wrong, I'm going to be happy for them if they're pregnant but like I don't get why them and not us?! We both have great paying jobs, our own trucks, a good size house. I'm so heart broken, I don't know what to do or how to feel. I'm obviously not going to hurt her by telling her how I really feel I just need advice on how to deal with this with my husband