pissed at him and I shouldn't be

My fiancé has been working late all week for this new committee at work he was selected to be on. He's super excited about it. But I'm super pissed about it. He's home by 330 every day. Lately it's 6 or later. And today here it is 648 and he's out to dinner with the committee people. I'm pissed. I shouldn't be. But I am. I'm alone and depressed and I hate it. I'm pregnant and miserable. And I feel like he'd just rather be out having fun