If you want to see a vagina everywhere you look perhaps you will. Maybe you could paint some suspicious flowers and be famous.

As for any deeper over arching meaning on anything in the movie let me deflate them simply by pointing out that the movie is not that intelligent. Exhibits one through 258 will not be broken down in this post. Instead, just watch the movie and drive a truck through all the plot holes, bad lines, and poor research. Just how often does third generation night vision equipment get sent home with a soldier?

However, to dissect your deep throating scene I would hazard a guess that since this movie has a basis in horror the idea is to have aliens reproduce in the most terrifying way possible. Thus, they force something into the body and it explodes through the chest. Our options are orally, through the anus, genitals, or perhaps ears. I think ears are disqualified for being to round about of a way to get to the chest and the sexual ones for these movies not wanting to cross over into the smut genera.

As for why the woman is pregnant:

Simply for fear and disgust factor. I highly doubt a fear of ambiguous sex played a major conscious or subconscious role in the decision making process. I could further delve into a tangent about how the writers tried poorly to make the hybrid a true protagonist, which was completely unnecessary, but I will refrain. However, possibly killing pregnant women was to further us as an audience agreeing with ourselves that, “yes, I do hate this alien hybrid and ache for predator victory.”

…

Then again, it did have some awful writing and I don’t think it was that deep.

Anywho, get a real job hippie.