Could I be pregnant? HELP!?

For the past week or so I have been feeling queasy at different times of the day. I often get headaches and am very tired. I had my period but it only lasted 4 days instead of the usual 6 and it was very heavy (it is always heavy the first few days). I just recently went through a bad break up and thought that these symptoms might be from the heartache and stress but they are getting worse. What do you think?