Jackson Rathbone is worried "about the practicalities" of being a dad.

The 27-year-old Twilight actor and his burlesque dancer girlfriend Sheila Hafsadi announced that they were expecting their first child together earlier this month.

Jackson is overjoyed with the news and hopes that he is able to get to grips with the nuts and bolts of fatherhood swiftly.

"I'm only nervous about the practicalities being a dad's one of the greatest things in my life I could ever hope to achieve," Jackson gushed to E! Online Tuesday night at the red carpet premiere of upcoming thriller Gone.

Jackson is elated with the way he and Sheila learned about her pregnancy.

"We found out together, we were very excited," he shared.

Sheila, 24, is said to be five months along and the duo are already making big changes in their life in preparation.

A source told Us Weekly that Jackson recently traded in two of his vehicles and purchased a more family friendly Lexus Hybrid SUV.

Jackson is best known for his role as Jasper Hale in the hit Twilight movie franchise.

The actor will next be seen in The Twilight Saga: Breaking Dawn Part 2, which will premiere this fall.