I personally elected not to dye my hair during pregnany. Just one of those things where I was like "well the chances of it causing an issue are slim, but I don't want to live with the "what if's"
I have been told it's fine to get your hair dyed and bleached professionally cause they do it in such a way that it's not right on your scalp.
Can't wait to have baby. On my list of things to do once he's out is to bleach my hair and dye it pink again.