I agree with SM.
I've also stated my theory on the egg before.
Someone else made a comment regarding what people think the film makers intended in making alien 3 in relation to the egg.
Let me be clear: I in no way believe that my theory is what the film makers intended. The film makers intended something quite different. And given the production problems of Alien 3 - the egg on the sulaco was a plot device pure and simple.
However, I am a fan of the franchise. So much so I've written fan fiction. I grew up with these films. I LIKE trying to explain plot holes. Call it a hobby.
To date, I have yet to see a theory about the egg that is PLAUSIBLE apart from my own. Correction, there's probably one more theory. Forgive me if i sound conceited because reading this back I even sound conceited to myself.
So out of all the theories that have come and gone, i've only known of 2 that are halfway plausible. The rest are just too far fetched.