Hey Calluna - first off, congratulations!

Secondly - it will be fine. I didn't find out I was pregnant with DD until nearly 10 weeks and boy I did absolutely everything they say not to do - from drinking in smoky nightclubs till 4am to eating all the naughty foods and working in a petrol station (so inhaling petrol fumes pretty well all day every day) and no pre-pregnancy vitamins at all. She was born perfectly fine. In the early stages they're snuggled nice and safe in your pelvis and the placenta IIRC is yet to take over at 4 weeks.

The tiredness sucks donkeys but it will pass. So they keep telling me :/