Of course you could be pregnant, I would wait a few more days and then test again.
Good luck for whatever you are hoping for.
If you have unprotected sex, your chance of getting pregnant is 25% for a given month.
Take another test, if negative then retest again in a week. If at that time you still dont have your period and are unsure of what to do, see your doctor.
there is a great possibility! test asap!!!!!!!!