In the Alien movie, Kane is attacked by an alien facehugger which implants an embryo inside him. The embryo gestates in seemingly a matter of hours to become a chestburster.
In the Aliens movie, the marines find the colonists glommed to bulkheads inside the generator. Long dead. Mostly, that is. One colonist is still alive serving as an incubator for the queen's offspring. The marines kill an infant alien after it bursts from a colonist's chest.
According to this question, after most of the marines are killed, the survivors say a rescue would take another 17 days, the amount of time for a ship to reach them from Earth. Using that, we can assume Newt was alone on colony LV-426 for at least 17 days and perhaps a couple of weeks longer.
Did the alien embyros take weeks to gestate in the second movie? Or was the hapless colonist captured by aliens mere hours before the marines arrived?
How much time do alien chestbursters gestate inside human hosts?
Answers from the movies, canon books, script writers, or other authentic sources are appreciated.