I am not a doctor, but I have heard of people still getting their period while pregnant. If your not sure, get tested. NO, as a nurse I have heard many people say that they had full or lighter periods when they were indeed pregnant with their child. The only guarantee is no sex, unless you are willing and ready to take that chance. Babies have been born, although extremely rare, to couples who both had been "fixed" to avoid pregnancy. It only takes the one sperm.