I guess tmi but I’m just trying to understand how to explain this to my SO

So for some reason I’m not into sex at all not just that in general but anything sexual kind of just bugs me and I have no idea why he’s just constantly trying to do something anything at that. It’s kind of like I feel weird about doing something. I know it’s kind of dumb to be putting this out there but I just want answers sort of or a way to just explain to him that sometimes this is normal. It started about the time we found out I was pregnant and nothing has really “gotten me in the mood”. I don’t know if this even makes sense either 😂🤷🏼‍♀️