S/he will need a buddy. Don't take anyone's word for what sex they are -- put the two side by side and turn them over and compare their private parts. You want same sex pairs -- guinea pig pregnancy/birth are pretty dangerous, not least because the pups are HUGE in relationship to the size of the sow.
That is a VERY young cavy! Babies this young especially need the companionship of another piggy as they are frighteningly vulnerable and lonely. Plus, it is easier to pair them when they are this age. Please do consider getting it a cagemate sooner rather than later. What a cutie!
Also, you'll need a cage larger than any pet store sells for three pigs. Three pigs need at least 10 square feet, if not more. A smaller cage will work while they're very young, but crowded conditions cause aggression, and ears get eaten.