If the woman is on top while having sexual intercourse and the man ejaculates in her, is it true that the semen will run out and there is a very low chance of her getting pregnant?
No matter whether you're doing it in the missionary position, woman-on-top, doggie style, spooning, or standing up, a woman has an equal chance of getting pregnant during unprotected sexual intercourse. The idea that woman-on-top leads to lower chances of conception is a misconception, a myth, and misinformation.
Regardless of a woman's position during sex, if a man ejaculates inside her vagina without using contraception, there is a possibility of pregnancy. After all, 300 to 500 million sperm are typically released in a single ejaculation. Sperm can swim in different directions (including upwards) when they spurt into the vaginal canal. If a woman is ovulating, healthy sperm can potentially swim through favorable cervical mucus. If it meets up with a healthy egg, conception can occur. Others may detour down and trickle out of the vagina (for more on that, you can check out Semen drips out after sex).
In addition, a woman can become pregnant from a man's pre-ejaculatory fluid (or pre-cum), as it can contain sperm.
It sounds as though you are eager to avoid pregnancy. If that's the case, then it makes sense to talk with someone about contraceptive choices to prevent pregnancy. For further info or help in choosing contraception, couples may want to speak with a health care provider.Alice!