15 weeks and 2 days getting mine highlighted right now.
Yupp... aslong as its not harsh dye. I dyed my hair with ammonia free hair dye as soon as i got to my sencond trimester (same dye i always use) and it dident take at all. My hair is usualy awsome with dye... so beware it might not take or last long =·\
As long as the dye is ammonia free your good to go :)