I Have Natural Black Hair

I have a question! I have cornrows that have been wrapped into a bun, but my stylist had also straightened my hair (by blow drying and combing it). I know that if I wash my cornrows, they will become curly again. Will the curliness ruin the braids? I am worried because not only did I just get my hair done, but I got it done so that I could look nice during upcoming job interviews, so I don't want to look bad. Does anyone have any advice?