Answer:
No. There is no possible way to get pregnant from oral sex, which is fellatio when it involves the penis and cunnilingus when it involves the vagina.
Typically, you can only get pregnant if ejaculated sperm reaches your ovum (egg). However, if your partner has some sperm in his or her mouth just before s/he performs cunnilingus, there is a chance. But if you both understand how babies are made, then this is extremely unlikely.
Even if you do swallow semen, it goes through the body in a completely different way than if you have vaginal intercourse. Also, the acid in your stomach will kill any sperm. There is no chance that sperm from your stomach will reach your egg(s) because there is no reproductive connection to the digestive system.
Remember, of course, that you can contract sexually transmitted diseases (STDs) such as chlamydia, gonorrhea, HIV and herpes from oral sex. Fellatio is much safer with a condom.