You can’t actual hav e aperiod while you’re pregnant, but you can have some spotting for a number of reasons. You should make an appointment to have a blood test, because it could be one of two things; a false positive test, or you were pregnant and for some reason or another ended up miscarrying. Did you have cramping accompanied with the bleeding? and if so, was it worse than you normall have with your period? Also, it’s worth mentioning that if you are worried you are pregnant, you may trick yourself into having the symptoms, and also delaying your period. But my advice would be to see a doctor asap. I hope I’ve been of some help, good luck! 🙂