I have been very stressed the past two weeks. how much does stress affect a period? will it delay it by too much?

Likely not: You are right that stress can affect our periods. I've definitely had patients where that's seemed like the case, but it is very rare. The body is a powerful thing, and most women, despite enormous stress, will still ovulate and have a period. Extremes of weight (too thin, too heavy) are more likely causes for irregular period. As well as thyroid or pituitary problems. Check with your doctor!