Alone time

Is it wrong for me to want to go away for a weekend by myself without my fiance? I have a son and he has a daughter I'm currently pregnant by a bit over a month and I've been wanting alone time for awhile now but he's always been against it

How do I get him to understand that he has his friends to hang out with and they relate to different things and many levels I don't really have anyone that I connect with on a consistent basis the way he does and between his daughters mother's drama and helping him sort his way through that sometimes I just need a second to myself and I don't think he gets it bottom line I don't have to go out of the country I just want me time