Does Alien Romulus have a post-credit scene?
NO, but reading this makes you contractually obligated to stay to ensure no facehuggers were harmed in the making of this film.

Related:
Alien (1979)
Aliens (1986)
Alien 3 (1992)
Alien Resurrection (1997)
Alien vs. Predator (2004)
Aliens vs. Predator: Requiem (2007)
Prometheus (2012)
Alien: Covenant (2017)