sativa`s are lower yielders than indica`s. they usually have fewer bud sites than indica`s, and take alot longer to flower and mature. the longer you veg. it, the more you`ll get. you have at least 3 more months of flowering before you will be able to consider harvesting.
i hope you have the patience because the buzz from a sativa is much more cerebral,motivating, makes you think and do.