I'm 15 weeks pregnant, very excited to be a mum. My pregnancy has been straight forward so far and apart from weeks of nausea but my mood has been great and stable throughout.
What I'm trying to point out is that I'm not depressed in any way and feel happy, excited and positive about everything.
However I've found I've lost interest in a lot of things I used to enjoy. Such as reading books, shopping, hiking, decorating etc. I'm studying part time but have such little interest in doing my assignments, I can't seem to find any motivation to study 
Could this just be down to pregnancy tiredness? Thesedays I am happiest snuggled on the sofa with my dogs/partner and watching tv, but it's making me feel like a bit of a hermit, a boring hermit!
Now that I'm in the 2nd trimester I was expecting a bit more of a spring in my step but it's not happening yet!
It seems if something doesn't relate to being pregnant or having a baby, I have little to no interest in it. Is this normal? My brain feels incapable of concentrating on reading a book right now, or on anything really. Dreading my next assignment, I've barely done any prep for it.
I'm 37 if that makes a difference. Anyone else had this in pregnancy?