Correct the original idea for Alien - put into a mural that wasn't really used and a scene that was ultimately deleted - was Egg to facehugger to chest burster to adult that implants victims who turn into eggs completing the cycle.
Although arguably not cannon I also remember an interview where Scott noted in his view the Alien only had a short time active, like certain insects, and that by the end its already nearing the end of its short life which is why it finds a hidden spot in the shuttle and is initially slow to attack Ripley. It had implanted others that would create eggs and therefore its cycle was over.
As all of this either wasn't included or not made explicit Cameron was able to introduce the Queen. A move that arguably made the Alien just a little too familiar to certain insects but did give him both "something new" and a heck of a good climax to his movie.
I just wish that rather than the lame termite egg sack they'd gone for a much more bio-mechanical egg laying machine design with the Queen attached in a similar way to the final film. I always felt that aspect of the Queen was a bit of a let down and too much of a deviation from Gieger styling. Probably budget and time were the causes but given Cameron designed a pretty damn good Geiger like Queen it's a pity he didn't extend the effort to the egg laying too.