People.com said Edwin Merrino was arrested Tuesday for allegedly stalking Spears, 17, and her fiancee Casey Aldridge -- who have been trying to keep a low profile in Mississippi since Spears revealed she was pregnant in December.
Merrino, who has denied harassing the couple, was released later in the day after posting a $1,096 bond, People.com said.
Spears, who plays the title character on TV's "Zoey 101" and who is pop star Britney Spears' younger sister, is due to give birth at the end of this month or in early July.
Exploding whale video goes viral on Internet
Selena Gomez drops F-bomb, walks off stage during Jingle Ball performance