If the seed is feminized in 99% of cases it will be female.
If the seed is from some weed that you smoked and the like, then it can be any gender, but you will know that before flowering, it depends on where you plant, if you plant inside, you will find out after a while when you switch the lamps to 12/12, if you plant outside, you will find out before flowering, the males start a little before the females to bloom, so they also show the sex a little earlier... if you are in the northern hemisphere after the twenty-second of June, pay attention from then on, the only question is when the plant will show the sex.
Happy Growing!