Its ok to dye your hair. I got a book from my doctor and it said its fine just be in a ventilated room.
I dyed mine with perm dye at 13 weeks and I was fine. You're fine after 12 weeks but they warn you that it might not take dye to your hormones x
Its ok after the first trimester. My dr sed so.
Im a hairstylist. as long as you are in a ventilated room dont worry about it. The only reason they recommend not coloring when pregnant is because hormones CAN do weird things. Although it is uncommon your color might not take right because of the hormones. I dyed mine yesterday in the bathroom. I just kept the door opened. No worries!!
Henna is safest, then demi and semi permanent hair dye, then ammonia free permanent hair dye ... in my opinion. Henna you will have more luck with natural colors... semi/demi permanent hair color unnatural colors such as Manic Panic brand... you can get ammonia free box hair dye like at Walmart or Target or wherever...