Advice needed!!

So basically here’s what’s going on.

My period is a week late. So as one does, I started getting concerned, but I didn’t really think I was pregnant. I took a test anyway and it says negative. So I’m blaming it on my sudden lack of activity, diet change, stress, and everything just going on.

Additionally, the last time I was sexually active was over a month ago. I don’t have any other symptoms, besides missed period. So I really don’t think I am.

My main question is, should I be concerned it’s like a medical issue? Or is it possible because of everything go on, and the sudden change in everything I might not even get my period?