Anxiety about husband going out

I’m 36 weeks pregnant, so I’m a little bit vulnerable at the moment and I have very low self esteem.

My husband started a new job 7 months ago and he’s told me his friend he hangs out with is having an affair with one of the girls in the office.

When him and his friend go out they usually end up meeting up with this girl and going for drinks with her and her friends.

I know the fact that he told me about it shouldn’t sound any alarms but since his new job he’s been distant, he’s always going out at midday for drinks and not coming in until 3am(which he’s never ever done before), he’s snappy and doesn’t seem interested in me.

I’ve outright asked him if I should be worried and he’s said no but everytime he goes out for hours on end I just sit at home worrying that he’s seeing or going to cheat on me with someone else.

He’s currently out now and I’m a nervous wreck but I don’t know what to do about it....