I've been stressed to the max for this passed month basically and my period used to start around the 10th, and then it changed to the beginning and now it hasn't come yet. Is my stress causing this or is it changing?

Stress will absolutely cause your period to either be late or have you miss a month.

Find an outlet for your stress. Take a brisk 30 minute walk each day so you can decompress from what's going on. Exercise will help settle your body and will help reduce your stress levels.

Don't forget to reach out to someone close so you can talk about what's going on. Bottling it up only worsens the situation; talking about it to a neutral party can help you see it from a different angle.

And most friends / family want you to be happy so it also helps them when you reach out. Good luck.