Hair Dye during pregnancy Brunette with greys!!!

Becky
So I'm 31 and have dark brown long hair but have been getting greys since i was about 20! 
Always dyed my roots brown with a semi permanent hair dye at home, to catch up with my hair. Hate roots so do it 4-6 ish weeks depending on if I'm going out for a special occassion! 
So now the realisation has hit me from reading things that you should avoid 1st trimester, that's another 6weeks as I'm 6 weeks now! And actually it's not good at all because of the fumes and also the chemicals passing to the baby through my skin/blood!!! 
I know the importance of a healthy baby, took me 7 months TTC for this my 1st ever pregnancy, but honestly hair is such a big deal and even more so if your brunette!!! 
Any words of wisdom???