Low sex drive

Hi all I’m 20+2 and I kept reading everywhere that’s sex drive was meant to go up in my second trimester but it’s plummeted and I don’t want it to effect my relationship with my fiancé.

Emotionally I’ve grown to him more through my pregnancy but sexually it seems to have decreased and I’ve talked to him about this but when I say no I can see the disappointment on his face even though he says he’s not worried.

Can someone please reassure me that I’m not the only one?