Ive been the same way... Im 32 weeks. I do the cooking and cleaning since my husband has the job and its becoming a bit harder... I get tired wanting naps all the time now but when I do have energy I try to continue getting things done around the house.
Enjoy it, take rests. Soon you will very busy with the little one. I'm 33 weeks, I'm mostly exhaustedddd, I don't do much either.
Yeahhhhhhhh it's natural.
You'll perk up eventually when you hit your "nesting" stage