My period came four days early and my period is never irregular. On the first day I spotted (which is something I never do) before my period, the second day it was unusually light and the next two days it was heavy then it stopped, I also had unprotected sex two weeks earlier. What could this mean?

You're likely just having an off month, it happens to all of us. Sometimes stress can bring your period on early, or late, also medication, illness, and many other things can change you schedule.

If you're worried about pregnancy than take an hpt, make sure to use first morning urine as it's more accurate.

If it's negative wait and see how your next period goes.

Good luck.