People say hair dye is okay while pregnant but what about hair bleach?

Okay so - while I was still in my first trimester (I'm currently 21 wks) I decided on a whim to re-do my hair color which I've done many times in my lifetime with the same products. I was in a well ventilated room, nothing unusual, feelin fine but that changed pretty quickly after I mixed the bleach. As I was getting ready to apply it to my hair I started getting dizzy and felt extremely faint. Luckily my SO was in the room with me and got me in the shower and away from the bleach assuming that's what it was. But even after googling I couldn't find anything? So I never knew for sure if it was me being that way due to just being pregnant or if it was the smell.. I haven't tried to do anything with my hair since and haven't planned to since that freaked me out a little. But I still wonder about it. Has anyone here hair any experience with bleaching their hair professionally or otherwise during pregnancy?