Haha, hormones - I know this feeling. My brain is always kicking me and yelling "BABIES" at me. But, you're not crazy. You're planning ahead, and trying to anticipate problems that children might create with Partner - this is a good thing.
That said, you're probably worrying about things that are almost /too/ far ahead in the future. Partner and Boyfriend haven't met yet, Boyfriend hasn't been around past NRE time, etc.
My two cents on the matter.