I'm getting clingy?

My fiancé and I are best friends. We spend a lot of time together. He is in the army full time and I go to school full time. So we spend hours apart throughout the weekdays. He went to the field for a week and there's only two days left before he comes back and I feel uncomfortable. Like I literally feel miserable that he's not here and it's making me feel whiny and clingy. I'm not usually like this so I'm a little thrown off and don't know how to deal with this. Is this normal?