Just remind yourself that most people don't even know they're pregnant before 4 weeks so they do all that stuff and go on to have normal fine healthy babies. And to avoid stress, don't eat stuff you know will stress you out for anyone else's sake, your allowed to say no to food! And most people are pregnant and towing around another small child (eg I have a 15kg 2yo that has insisted on me holding/carrying her all the time since I was about 5 weeks pg, I'm now 11.5 weeks and she's still at it!) and it works out fine. Try not to stress, tho I know it's easier said than done! Good luck x