AITA for not coming to Thanksgiving dinner after I got uninvited and then reinvited?

My parents and siblings get together at my parents' house for Thanksgiving and generally stay for most of the weekend. <br><br>My husband, our toddler daughter, and I live about 30 minutes from my parents. We visit pretty often. Everyone gets along okay. The problems started after my brother and SIL had their first child (my SIL was full term, while my daughter was 3 months premature). Suddenly, everyone was obsessed with my niece. My husband and daughter got lost in the process.<br><br>In Sept., my SIL posted on FB: "Our beautiful baby <name> was born <date> and stole the hearts of so many."<br><br>My husband was furious about that, since we'd been trying for years and suffered several miscarriages before our daughter was born after a high risk pregnancy.<br><br>A few days after my SIL's post, my parents asked when we would be coming over for Thanksgiving. I told them we had other plans.<br><br>Now, I am being begged to come with my husband and daughter so that we can be a whole family for the holiday. I told them that I already accepted another invitation and couldn't possibly change my plans.<br><br>My mom and dad are both telling me that I am the asshole. I told my husband about the invitation and told him what I said to my parents. He was angry that I didn't tell them sooner.