THere are lots of threads on this already as I think a lot of us colour our hair.

I was told that foils are a better option as the chemical isnt sitting on your scalp. If you get an all over colour the chemicals are sitting on the scalp and there isnt alot of research into the damage it causes.

Keep in mind as well that your skin/scalp and nose will be alot more sensitive now you are pregnant and you should be in a really well ventilated area and if it starts to hurt tell the hairdresser straight away.