My period has always been regular, but in July it came and August it has been off by a few days. And this month it has not came yet. I thought maybe I could be pregnant. But the home pregnancy test came back negative. Not sure what to do about it. Is this normal?

Stress and other factors may delay a period as long as a week. Did you do the pregnancy test with first morning urine? If not try that or wait another week or two to make sure you're not just late. If your period doesn't come at all this month, try another pregnancy test with first morning urine.