Unless they are using misdirection quite a lot. Crudup's character is definitely facehugged.
The couple that is attacked by a Xeno while getting it on in the shower and I assume that is the the Xeno that erupted from Crudup's character.
Would that couple realistically be in that sort of mindset if Rigby's character had already backbursted giving birth to what I'm thinking is the neomorph?
I think its safe to say that either Crudup or Rigby go first. And I might have it mixed up. The classic Xenomorph might be from the backburster/Rigby and the neomorph might be from Crudup.
And lastly, some of the events might be happening simultaneously.
Ejogo's character and Crudup's character seem to be a couple and neither of them seem like they've just lost their SO during the facehugging scene or the backburst scene.