Are these male preflowers?

Yes you have a boy! You can grow it for its pollen to breed if it has good genetics. Or grow it to make teas and ointments. Or if you are looking for just bud then chop that sucker

Thanks for your answer. They are actually located near the top of the main stem. Elsewhere I think I actually see calyxes. Would it be eventually safe to cut the top of the plant and hope it will only produce calyxes everywhere else? Hopefully, I have two other plants which seems to be female.

Nanners are individual stamen that form inside your buds during flower on a female plant. Those are not nanners. Those are full fledge male flowers. Each flower contains many stamen. They are forming in a huge cluster if its hermie it's very hermie. But I do not see the supposed calyx referd to below.... there are no female flowers present in your pics. Even so u would not see a female calyx as its inside the flower. You would see a female flower bract and pair of stigmas... which are not present. Happy growing and stay lit fam.

Oh Buddy, these seem to be nanners, I've also noticed a calix. Hermie to me 90% 😔