Of course it's normal for us to miss those we cherish — especially when we're apart for long periods of time.
Have solace in this: it's almost Thanksgiving. You're nearing the finish line and you will see your sweetheart soon enough.
Until then — don't mope. Don't get super clingy on the telephone. (Though she'll be flattered by your missing her, she's also probably having the time of her life. However, if her boyfriend's being a party pooper, it can taint her experience.)
And be strong. Start planning the wonderful, romantic dinner you'll share her first evening back.