Safe to color hair when ttc?

Hello ladies was wondering what everyone thought about coloring hair while ttc...since no one really knows the exact time of conception you could run the risk of coloring while in the very early pregnancy stage..I am a hair stylist but am a bit concerned because I have had 2 mc and I use double 40 volume directly on the scalp for 35 min not bleach but high lift color..for those non cosmetologist a that's the highest volume you can use nd usually is only for blonde hair...help opinions??!?!??