Well the symptoms you are suffering from could be due to PMS.
But if you want to completely rule out pregnancy
the questions you need to ask is did I have unprotected sex in the recent past?
If yes, then there is always a chance of conception. Wait out a week and see if your period starts, also take a home pregnancy test in a couple of days., although the test is sometimes wrong, it is a cheap way of getting an answer right at home.
I hope this answered your question.