Am I over reacting?

So, my boyfriend and I havnt been together long but everything has been going great. We usually hang out about once or twice a week. I am leaving for alaska very soon and he is leaving for Michigan. I am leaving my phone back home and am going on a trip of solidarity. My boyfriend and I won't have contact with each other for about two weeks and today he invited me to go swimming so we could see each other before we leave. I said yes and told him to meet me at the lake and then he said "actually me and my other friend are going instead" I assumed he would allow me to join with them but he didn't and told me he would be careful cliff jumping without me there... I'm a little upset? Am I wrong for being upset?