Its kinda long but I really need some advice!

I started working at my job as a receptionist mid october. And about a month ago my boyfriend proposed and we decided to get married in February. We're not doing anything big just a court ceremony and planing to leave for vegas for our honeymoon.. just the weekend. I asked for Thursday and Friday off and got it. Wedding is 2.5.15 at 330but now my boss wants me to work half day on Thursday and off friday. I agreed. Now today I got a phone call that my court appointment is changed to 1 pm. That only gives me 1 hour to go home and change:( I told my supervisor this and she said I can leave at 11. I guess what I'm asking is do I have a right to be upset or should I take what I got since I've only been working for about 3 months? My Co worker say I should call un Thursday but I don't want to get fired:( what should I do?