Yes, this can happen, especially if you take a test, it is possible to be pregnant and still have your period but its very rare. You can talk to your doctor and he can run test on you even an ultrasound to make sure. I had a friends who didn't know she was pregnant because she got her period every month the whole time she was pregnant and gave birth after her basketball game! She still played basketball because she didn't know she was pregnant and didn't even show at all! She went home to shower after her game and began going into labor, lucky for her she never really showed with any of her kids, she has 4 kids and not one single stretch mark she never got big but she did become regular after her first so she was able to know she was pregnant.
at 2:28 AM on Aug. 18, 2010