I’ve been acting different .. please read

The last 2 days I have 0 interest in interacting with anyone, not even my husband. I’m 30 weeks pregnant & I recently caught him talking to other women And very obviously looking at other girls - girls even I know - on social media. I don’t feel like anything is wrong but he keeps asking what is wrong and I just don’t know. I have noticed it myself but i can’t pin point what it is. Maybe something to do with what my husband has been doing? It has been weighing on me but I don’t feel that’s what it is but I suppose it could be? Unconsciously maybe. I just don’t feel like taking at all. I just sit here. I’ve been extremely quite. Anyone have any ideas? Or thoughts?