Am I upset for nothing?

I'm 20 and my boyfriend (fiancé without the ring) is 23 almost 24. We're temporarily living with his parents. I love his family. They're crazy, but what family isn't? Well his youngest brother (18) got a girlfriend about 6 months or so ago. She seems really sweet most of the time, even though they fight A LOT. Well it seems every time my boyfriend and I do something for the family she has to one up us. Today is future MIL's birthday and I worked my butt off to clean the whole house (i'm usually the only one who cleans after 5-6 people everyday anyways) and I cooked a big meal. She comes home from work, gets ready and says that she's going out to eat with lil bro & his girlfriend bc his girlfriend asked. I'm a little upset. It's little things like this all the time that makes me think they like her better. When he first brought her home to meet everyone, MIL said to my boyfriend in front of me "She's so gorgeous" "what's wrong are you jealous?" Like why would he be jealous ? We've been together almost 2 years?? He said "no why would i be?" But I actually had to leave to keep from crying. I try so hard because I just want his family to like me since I am going to marry this man one day and we're gonna be family. It's like they're tryna push me away. They even forgot my birthday this year (i don't expect anything, i mean i'm 20 but i didn't even get a happy birthday from any of them). Am I wrong to be upset?