I feel so guilty!

I need a little encouragement here. Pre-pregnancy, I was a bit of a health nut. I run lots of races, run 30-40 miles/week, lift weights 5 days/week, bike a lot and and yoga 3x/week. It's pretty normal for me to workout twice in a day. Now I'm 6 weeks into my first pregnancy and the fatigue/nausea/generally not feeling like myself has me cutting back quite a lot. This week I only ran 18 miles, and even though I still made it to the gym 4 days this week, I feel guilty. I usually take a rest day on Sundays, but I took one on Friday and now I don't feel I deserve to take today off too. Part of my brain says, "you need to run 8 miles today!" And the other part just doesn't feel like it. Logically I know I'm being silly, but I'm having a hard time not feeling guilty. Help!