No wait till your first trimester is over
My doctor made me wait till 2nd trimester
Highlights don't touch your scalp... My doc said it was fine. As long as it was through a pull through cap
Yes it is OK just be well ventalated area
Just understand they may not come out right because of your hormones make sure you tell your stylist so they can take that into consideration. It is okay to do any coloring while pregnant it isn't going to harm your baby. Doctors say don't do it because of the smell and most women do it themselves in their bathrooms.
I didn't dye my hair til then end of my second trimester