How much extra time am I adding by topping

I have some 3 week old plants, some of which are thriving. I have FIM'd 2 of them about a week after they sprouted. They are both good looking plants, but very short. All of these plants are planned to be mothers, but hopefully at least 50% make the cut. I want to clone for sex as soon as possible...so if I top them now, how long am I delaying having a viable clone that I can take from the plant? The 2 I topped have nice growth, but I have no way of knowing how long it will be until they have usable branches for cloning.

Thanks in advance,

MM

Here's what I'm working with currently. I have a 400W MH rockin 24-hrs a day. I just got it hung yesterday, so I haven't seen any big increases in growth yet. I also had little to no exhaust until today, so I stuck a 6" Max Fan pulling hot air out.

I'm hoping that the lack of an HID bulb and the poor air flow were what was causing the slow growth. I guess I'll find out soon enough.

Any answers to how long topping will delay me having enough growth to make a clone for sex?

I'd say another week before you can take clones.

If you would have topped them instead of fimming, you could have used the tops you cut to clone for sex.