Hormones?

I dont no if this is hormones or not but recently ive been all over the show about my partner. I keep thinking he will cheat on me and i dont no why, honestly because im having his baby i dont think he would but its all i think about and sends me in moods with him 😢 and when i say to him "youll never cheat on me will you" he tells me to shut up and stop being silly but i just have a feeling yano