You may be confusing the single 'hair' as a preflower when it is actually something called a stipule. Stipules are pointed hair-like spikes that come out at every node (there are usually a pair - one on either side of where every leaf stem attaches). They are on both male and female plants and will be seen at every node, although their appearance will vary depending upon how new the growth is. Older stipules will be larger and thicker and often stand out farther from the stem, younger new growth will sometimes look like a hair from a female preflower but without the 'pod-like' growth. If you're seeing singular growths that appear pointed, rather than groupings of more rounded ones, you should be seeing hairs eventually. The boys will usually show faster, and always give themselves away with their multiple pods. In any case, you have plenty of time before they would be mature enough to pollinate any girls. Give it a few days to be sure they're really growing balls before you chop them. It will be very obvious long before they're a danger, and you don't want to toss a girl by mistake!
Here's early Man-hood for your reference.
And another sign...
