Anyway, you can find pictures of flowers in General Viticulture or in Foundations of American Grape Culture.
Female vines have a large ovary and the stamens curve down under the flower.
Male vines have little or no ovary and the stamens are upright. If you look at the three vines you have, you should be able to tell the difference easily. Maybe it's male. They only consist of 2-3 berries. If they are wild vines, there is a chance they are males.