R.,
Some people will continue to have their first menses after conception. It does happen. Also, there are some rare women out there that have continued to have their normal meses every month throughout their pregnancies. If you continnue to have any pain or cramping, or if the bleeding goes on for longer than normal, then you should definately contact your physician. The other thing to note here, is if you have an rH negative blood type, any spotting you have needs to be reported right away. Good luck and may you have an uneventful and happy pregnancy!