Can a boy nub turn to girl nub a few days later??

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Any idea what that could be if it's not the nub??

So it turns out you lovely ladies were right - it's not the nub!
I picked up my scan results and they gave me ten or so photos I hadn't seen. Unfortunately they're of terrible quality, but I can work out that what I thought was a forked boy nub, appears to be the umbilical cord coming from the tummy!
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