Pregnancy hormones?

This is crazy and It has never happened to me before, so I'm just seeing what other people say or advice, I'm 18 weeks pregnant with me and my husbands 2nd child, have been together for 8 years and married for almost 2 years, remind you that this has never happened before, but the last couple times we have had sex I end up crying and I hid it from him, I'm not crying because it hurts because it doesn't, I'm not crying because he's making me have sex or I want to stop that's not it either i have wanted to have set, it's not because it's bad because it's not, so it's nothing like that and i dont know why it's happening, I wanted to talk to him about it just so he knows but I don't want him to feel bad about it it's not his fault or anything he's doing wrong and I don't want him to think we can't have sex anymore or something, I don't understand has this happened to anyone else? It has to just be pregnancy hormones 🤦🏻‍♀️