Im wondering if its possible that im pregnant or if im freaking out abour something thats really nothing.

Im 20 years old and have been married for 10 mobths.

My cycle has always been 28 days on the spot. But my last few cycles have been weird.

I started one period on September 9 th which was when it was due, but my next period came on september 25th 11 days early.
Today on October 4th I've had really bad cramps, a headache all day, and have felt nauseated since i woke up.

Is it possible im pregnant? Or are my symptoms nothing to worry about?