16 and Pregnant Star Arrested for Stealing Pregnancy Test

According to the police report, the 20-year-old MTV star stashed a First Response pregnancy test in a hooded jacket ... and then "took it to the restroom wit her and used one."

Purvis allegedly tried to sneak out of the store through a side door ... but she was busted by store security ... who put her under citizens arrest and called local police.

According to the report, the pregnancy test was valued at $15.98.