OhNo I'm going to try and say this gently and tactfully, but that isn't a forte of mine, so please bear with me and try to take this with the good wishes it is intended with.
Your DS may be NT, he may not. Its too early to definitively tell right now. I suspect that you have been keeping an eagle eye for 'signs' because of your and your DP's history, so you are best placed to know if there is likely to be any medical justification for assessment.
But this isn't assessment. Not yet, and it may never need to be. This is discussing potential intervention and a bit of extra help. Lots of kids benefit from a bit of early intervention, and the vast majority never need anything further than that. This isn't necessarily the start of a lifetime of difficulties for your son.
All that said, I do think you should seriously consider grabbing any and all early help that is offered (this is where the lack of tact may come in, sorry).
Your son may well be picking up social difficulties from your partner and you. In the same way that he's picked up your accent, your turns of phrase, the family terms ('doofah' for TV remote, that sort of thing). That's not a bad thing, any more than the accent or anything else (apart from maybe 'doofah', any fool knows it is a telly bug ) but it does mean that your son may benefit from a bit of more focused work on his socialisation skills to help counter what he is picking up intellectually from you and allow his innate skills to come through.
I'm trying really hard to make sure it doesn't sound like I'm saying this is your fault, because it isn't. Its one of those things. Some kids inherit a double crown, some get wonky teeth, some get social processing difficulties. It is what it is, but teaching coping strategies to a kid with a social processing issue is a hell of a lot easier than changing a double crown, and cheaper than fixing wonky teeth.
Both DP and I are at the milder end of HFA and have social difficulties. Our DS so far appears to be completely NT, but when he first started nursery, they flagged a few of his quirks as potential indicators of HFA. His quirks were family quirks he had picked up by copying the behaviour modelled by me and DP. Nursery incorporated a bit of extra social situation work in their group sessions, so DS wasn't singled out at all, but it just gave him that little bit of an extra nudge in the 'right' direction towards societal norms.
We are now about a year on from that first quiet word that nursery had with me. I dropped him off this afternoon and almost tripped over all the kids who came over and mobbed him, wanting him to play with them. He has some quirks still, but they are just one facet of his personality, not an overwhelming difficulty for him to surpass.