India, Aug. 14 -- A frantic search is underway in Rehoboth, Massachusetts, for a missing pregnant teenager, Kylee Monteiro. The 18-year-old has been missing for nearly a week.

"She's timid and scared and doesn't know how to be on her own," said her sister Faith Monteiro, according to CBS News. Her family has stressed that it is extremely unusual for her to leave without contacting anyone.

Faith shared a post on Facebook, seeking help to find her sister. "Hi this is my sister Kylee. She was last seen in Rehoboth on Thursday. If anyone sees or hears from her please contact me at 330-481-8521 or the Rehoboth Massachusetts police department at 508-252-3722 Any help is appreciated," she wrote.

Rehoboth and state police with K-9 units are se...