1st trimester exhaustion!

I am 5 weeks 6 days into my first pregnancy’s and starting to experience the exhaustion I’ve been reading about. Today, I ran my usual 5km park run race and gave it my absolute all, felt like I had beaten my usual time but in actual fact I had added 2 minutes on - despite eating the same breakfast as usual and having a great nights sleep. I wasn’t overly fussed about my time but about an hour afterwards my husband and I got ready for our usual weekend walk, at which point I had to get into bed and take a 2 hour nap! Never felt tiredness like it! I am due to see my Dr next week so I’ll make sure my iron levels are checked. It’s gonna be tough getting use to this 😴