Britney Spears has come a long way since her darkest days.

The once troubled pop star has got her life back on track, with regular access to her children, a successful tour under her belt and a loving and stable relationship.

But it seems that something may be worrying Britney. She looked anxious and preoccupied as her boyfriend of two years drove her to the mall yesterday.

Not herself: An unhappy Britney Spears goes shopping in Calabasas, California for new bikes for herself and her sons yesterday

In great shape: Britney has worked hard to get her life back on track

The blonde star kept her arms protectively around her body as Jason Trawick helped her out of the vehicle, almost cowering behind him as they walked hand-in-hand inside.

The pair were buying bikes so that Britney and her sons could ride together.

But while Jason inspected the merchandise it seemed the 28-year-old’s mind was elsewhere.

Britney wore a clinging pink sundress and matching flipflops, with her nails painted the same shade.

Preoccupied: It seemed something was worrying Britney, as she shopped with boyfriend Jason Trawick

Perhaps she was worrying about reports she is being threatened with a lawsuit by a former member of her security team.

Former policeman Fernando Flores, 29, quit his job after allegedly facing a series of bizarre seduction attempts.

He told friends Britney would walk around her house naked, and beckon him into her room.

He finally handed in his notice when her father, Jamie, chastised Flores for allowing her to leave the house without underwear, something he felt uncomfortable discussing with her.