Response:

That sense of familiarity with someone you do not have any previous history with that you can remember, is an experience that I think many people can relate to. 

Even without being pregnant or having recently suffered the loss of a loved one, when you connect with another person who elicits deep memories of intimacy and closeness, it will often bring up those feelings of familiarity. 

If those feelings remind you of a time that you still long for or a situation that was left unresolved, then it only stands to reason that you will feel sad at the prospect of this person now moving away. 

If that sadness does not resolve on its own easily, then you might want to explore it a little more to help get to the source so you can release it completely.

Love,

Deepak