Do I have the right to be mad at my best friends?

I, F18, have just finished highschool and am planning on going to University. The University I'm planning on attending is not in my hometown and therefore I will move into a student dorm in the city I'm going to study in. I have 2 best friends and we've always been a trio, in fact one of the other girls was already my best friend before the second one came along and made us a trio.

I know that many people have stereotypes when it comes to friendship groups with three people, but honestly this was really never a problem for me as we always did everything in a group of three and nobody was ever excluded or made to feel left out.

Anyways, I recently asked my two best friends if they already know where they'll be living once Uni starts (we´re all moving to the same city). They then told me that they are moving into a dorm for two people together and already have a spot secured there so this was not just a plan anymore, but a sure-thing.

They are not going to the same Uni as me, but it is in a reasonable distance from my Uni and in the same city (it´s like 20min apart). The fact that they just decided to move in together without telling me at all really hurt me and made me feel excluded, especially since I don't know when they would've told me about their shared dorm if i hadn't asked about their future accomodation.

It felt like they deliberately kept this a secret from me instead of filling me in on time. I understand that it might be more practical if I don't move into a dorm with them since I would then have a longer commute to my Uni. But why did they do all this behind my back and made no effort to include me in their plans whatsoever?

Do y'all think I have the right to be mad about this? This incident already occured like 2 months ago and I never confronted them about it or said anything since I didn't want to cause unneccessary drama, but I haven't been able to see our friendship the same since then and am honestly thinking about cutting contact. (other things have happened before and since then as well)

All advice and different opinions would be appreciated :)