Yes, you certainly can get pregnant if you have sex before, during, or after your period. That's because women don't always ovulate when they are "supposed" to, and because sperm can live for up to about five days inside the vagina.
The withdrawal or pull out method is unreliable, and is not considered a "real" form of birth control. So if that has been your only "method of protection", you've basically been having unprotected sex all along.
The only way to know if you are pregnant is to take a pregnancy test. In the future, if you do not want to get pregnant, invest in an actual form of birth control.