just dont go all the way to your roots because if it does it could harm the baby. i had mine professionally done and i told them i was pregnant and thats what they did to my hair.
Use foils. I was in cosmetology school with my first and my hair was a thousand different colors my entire pregnancy. My daughter is perfect
... Research shows that it doesnt harm the baby at all. If you want to play it really safe, color your hair in your 2nd trimester and make sure there is a lot of ventilation.
I wanted to colour and foil my hair (I am 5 weeks) and my doc suggested I hold off until the 2nd trimester. Just to play it safe.
The chemicals nowadays won't hurt your baby. I'm in the beauty industry, my best friend is a hair stylist, you're fine to color your hair