Is sex the only way to get pregnant?

I am wondering if the only way to get pregnant is to have a penis go inside a vagina directly? Would someone get pregnant if sperm were near the vagina, but not inside?

For a woman to get pregnant, healthy sperm must be get inside a woman's vagina, near the cervix around the time of ovulation. This does not mean that the penis has to actually enter the vagina; it just means that the sperm has to enter the vagina. Sperm that is in the general area of the vulva (the outer lips of the vagina) may work its way into a woman's body during sex. For this reason withdrawal of the penis from the vagina right before the moment of ejaculation is not a full-proof way for a woman to keep from getting pregnant. Neither is genital to genital contact outside the vagina, which does not involve penetration. Both activities may still deposit sperm somewhere in the female genital tract where they can swim their way up to the cervix and beyond. In addition, in the moment right before ejaculation, the penis emits a small amount of fluid that is used as a form of lubrication during intercourse. Sperm may indeed be present in this fluid, so there is a definite possibility for pregnancy even though ejaculation did not take place inside the woman's body.

However any kind of sex that leads to ejaculation but does not include penetration (either oral or manual sex), is not likely to lead to pregnancy. The sperm has to actually enter the vagina, travel through the uterus, up the fallopian tube and meet the egg. The possibility of this exists, but it is not large. It is important though to remember that if a heterosexual couple is not using a condom they are risking the transmission of STDs and HIV, as well as the risk of pregnancy. If a woman thinks she might be pregnant she should get tested at a nearby clinic or health care provider.

REFERENCES
a listing of scientific articles and texts used.