First time preggo question...

I'm 5 weeks pregnant with my first so this is all very new to me. I am wondering if it is normal to become very fatigued after doing simple housework? I just dusted, windexed, swept, and wet mopped my downstairs and I am seriously tired. My back hurts a little and I'm slightly out of breath. I am not in bad shape as I regularly exercise so I don't normally become out of breath with these tasks. I live in a townhouse so it's not like the space is huge. Is it normal to become fatigued? Any advice would be helpful. 😊