2 months what into veg or flowering you will never see sex while vegging unless its a weird plant or you have fucked up light cycles
You see the sex based on where its at in its life cycle. Until the daily light schedule is shortened, it'll never show sex (unless its an auto-flower).
If you have a plant in veg, for like 3-4months, they can show sex..... but won't make any bud yet. To get the bud, you have to shorten the light cycle. I vegged my current flowering plants for 2.5 months without seeing any sex yet. Not too long after the nodes start to alternate is when some pre-sexing characteristics start to show. For females, there will be a little upside down ice cream cone with two white hairs exiting the top of the upside down cone. The male presex will look like a ball, then two balls... in tiny clusters. I am currently growing some seedlings in flower right now. They started 1.5 weeks @ 24/7light from seed sprout, then moved them directly into flowering. Hoping to figure out the soonest I can tell sex and try a half assed sog. Just google search cannabis presex flower pics. It's very easy to tell which is male and female after you've done it a few of times. Be careful though..... I thought that one of my strains was showing male presex flowers, but it turned out to be female. You don't have to rush killing the male plants...... wait and make sure it IS a male before you kill it. The male plant is NOT a threat until the pollen sacs(balls) burst open. Hope this helps!
4-8 weeks of growth is standard for preflowering, dependent on strain. I grow a local indica strain that runs closer to 8 weeks. A fellow grower can sex them with his eyes but I need magnification. Three of us check each others plants and we run around a 90% success ratio in determining sex at the preflower stage. Beats digging 30 holes and amending the soil to get 15 females. Massive amount of images on the net for this subject.