hair dye/highlights

Laura 🇬🇧
Hi, I just wondered what people felt about hair dye and bleached highlights? 
I didn't dye my hair with my first so I looked pretty rough hairwise come due date. I already had an appointment for colour and highlights for my birthday in Feb. I will be 8 weeks by then. I don't want to cancel on the hand because it's my birthday and it needs doing badly already! However I'm feeling nervous about the lack of evidence. I could wait until after 12 weeks I suppose... how do other people feel about this, what would you do?