Could My Period Come Early?..

Aneicia
So yesterday I was at work and we was pretty busy. I stared cramping and didn't think anything of it. Sometimes at my job it's hard to rush to the restroom. I stared to cramp more and I felt a warm sensation drop. I thought it was just a normal discharge, but it was actual blood. I rushed to the restroom cleaned myself up. But I was really shocked My Period don't come until the next 13-14 days. I missed only one birth control pill. But it's strange this never happen before. My Period came about 2 weeks ago already.
What's going on?