I'm 28 weeks and I feel so tired! It's not quite like the feeling of being wiped out I had in the first trimester but at the moment I feel exhausted. I have the afternoon off and I'm in bed watching tv but I feel like I could go to sleep, though I probably can't actually get to sleep when I try.
A 20 min walk or being on my feet to do housework will leave my tired, eating a meal (possible particularly if carb heavy) leaves me exhausted and today I was walking for about an hour.
People talk about first trimester tiredness but not so much about being tired at 20+ weeks.