is it wrong of me to be upset?

me and this girl have been friends for around 3/4 years, usually we hang out outside of school like 2 or 3 times at least a month and usually she’ll ask if i want to hangout it’s not like i bother her to or anything and usually we have a lot of fun. recently like the past 3 months we haven’t hung out outside of school at all, she’s hung out with literally everyone except for me. and there’s been several times where at lunch in school or whatever she’ll not ignore me but kinda leaves me out and it obviously upsets me but i haven’t said anything about it cause i don’t want to be annoying or be over reacting. is it wrong of me to be upset?? please don’t be rude in the comments, it’s just been something that’s been annoying me a lot recently and i don’t have anyone to vent to or anything.