Yes you can it's less likely but still possible
not likely. getting your period means that your uterine wall is shedding the extra tissue it had built in preparation for a pregnancy. so menstrual bleeding is a sign that you have ovulated, no egg was fertilized so the next step in your cycle begins (period.) but as always, anything is possible.
It is about the least likely time in your cycle ... if the period comes on, then you can trust that the bleeding means you aren't pregnant.