US pop superstar Britney Spears has checked herself into rehab following her arrest last month on suspicion of driving while intoxicated near Los Angeles, US media reported on Sunday.The 44-year-old singer was arrested in early March and booked into custody by the Ventura County Sheriff’s Department on suspicion of DUI (driving under the influence).She was released soon after, and a representative for Spears at the time described the incident as “completely inexcusable” and said Spears would...