She can try applying for a visit visa to join you in Canada but there is no guarantee it will be granted. If it were granted, she could come and stay with you but she would not be allowed to work or study and she would not have health care.
For the future, you need to get married and you need to sponsor her for permanent residency. With the processing times being what they are, it is unlikely that you would succeed in doing that before the baby is born but the baby will be a Canadian citizen anyway because you are. You can find the forms here:
http://www.cic.gc.ca/english/information/applications/fc.asp but you would either have to be married or have lived together for a year before you can apply.