The chances are slim if you have been using the birth control as directed but stranger things have happened. I have never heard of anyone having all of these symptoms in a week of missing period. The best way to know is to go to the doctor and this way if your not pregnant they can find out what is going on the make you so uncomfortable. If you dont have the money for that the stores do offer good at home pregnancy test. You could have an infection of some sort. Good luck.