You can always run it by your doctor for peace of mind but am guessing they will tell you it is fine. :>) Even when pregnant, we need good hair!!
Yes it's safe to do im 39 weeks and dyed my hair all.thru pregnancy. The only thing is be careful wat colour you dye it as the hormones we give off may make it go a different colour.
I dyed my hair black and ended up with ginger roots were my roots are normally blonde. Thankfulky this only happened once
I'm 33 weeks and have dyed my hair like 6 times my doctor said it was fine just make sure you in a ventilated area. I used regular box hair dye. Never had any issues. There isn't enough chemicals absorbed into the skin to cause a problem