Can I wash or pee away sperm to prevent pregnancy?

No it is not.

Let’s dissect this so that you understand why not.

You don’t urinate from within your vagina⁠ (vagina: The internal passage leading from the opening of the vulva to the cervix of the uterus.) , but rather from your urethra⁠ (urethra: The urinary tract, where people pee from. On a penis, the opening to the urethra is at the head of the penis; on a vulva, the opening is above the vaginal opening and below the external clitoris.) , a very small, barely visible opening on your vulva⁠ (vulva: The name for the external genitals of people assigned female at birth. The vulva includes the mons, external clitoris, inner and outer labia, fourchette and perineum.) between your vaginal opening⁠ (vaginal opening: The external opening to the vagina.) and your clitoris⁠ (clitoris: A sexual organ both external and internal on the vulva and inside the pelvis of those often assigned female at birth that is similar to the penis, but serves no other known purpose besides providing sexual pleasure.) . To get a better idea of what I’m talking about, have a look at the first illustration here: Innies & Outies: The Vagina, Clitoris, Uterus and More.

During vaginal intercourse⁠ (vaginal intercourse: When a penis or sex toy is inserted into and held by the vagina while partners move their bodies as feels good to them for the purpose of either sexual stimulation and/or reproduction.) , if a partner⁠ (partner: In a sexual context, a person with whom someone is having some kind of sex. The term “partner” can be used for all kinds of relationships, not just serious ones. “Partner” can also mean the person someone is with in a romantic or familial partnership.) ejaculates, that ejaculate is going into or around the vaginal opening, and then the sperm⁠ (sperm: Reproductive cells of people with penises which can fertilize an ovum and create pregnancy.) in that semen⁠ (semen: Fluid which comes from the urethra of the penis during ejaculation, and which usually contains sperm.) move up through the vagina into the cervix⁠ (cervix: The opening to the uterus, the bottom of which is at the back end of the vagina.) . Urine doesn’t go anywhere near your cervix nor into your vagina, so it can’t wash away semen. It also, for the record, can’t wash away any viruses, bacteria or parasites when it comes to sexually transmitted infections⁠ (sexually transmitted infections: STIs: illness, infection and/or disease which is often or can be transmitted through sexual or other intimate contact, like HIV, Chlamydia or Herpes. Some people call STIs STDs.) . For more on lowering the risk of STI⁠ (STI: Sexually transmitted infections: illness, infection and/or disease which is often or can be transmitted through sexual or other intimate contact, like HIV, Chlamydia or Herpes. Some people call STIs STDs.) transmission, see Safe, Sound & Sexy: A Safer Sex How-To.

In terms of washing, again, when we wash our genitals⁠ (genitals: Body parts that are generally, culturally, scientifically or personally considered to be external sexual or reproductive organs.) , we wash the outside: our mons⁠ (mons: A mound of fatty tissue (skin) covering the upper portion of the vulva. In adult people, this area is usually where much of the pubic hair is.) , outer labia⁠ (labia: On the vulva, both inner (labia minora) and outer (labia majora) sets of skin with sensory nerve endings which surround the vaginal opening.) , inner labia, maybe right around our anuses. Even if you try and wash the inside or douche – which is always a bad idea, and it can cause imbalances in the vagina which can lead to discomfort or infection⁠ (infection: When harmful microbes, or germs, or harmful levels of microbes/germs, enter the body and multiply, causing illness. The common cold, flu viruses, sexually transmitted infections, chickenpox, impetigo, rabies and diphtheria are some kinds of infections.) – water, soap or a douche solution isn’t going into your cervix. Sperm swim fast. Even if you did an Olympic sprint to the bathroom after sex⁠ (sex: Different things people choose to do to actively express or enact sexuality and sexual feelings; often this involves genitals, but not always. ) to try and wash out⁠ (out: Short for ‘out of the closet’. When someone’s LGBTQ+ identity is known to other people.) your vagina, you couldn’t beat them to the punch.

The opening to the cervix (and you saw where that is if you read the whole of that article I linked you to: it’s the neck of your uterus⁠ (uterus: An internal, muscular reproductive organ in the pelvis. During pregnancy, this is where a fetus will develop. The lining of a person’s uterus is also the thing that sheds every menstrual cycle in what we call a period.) that juts into the very back of the vagina), is incredibly small. Part of why that is is to protect your reproductive organs. If that opening wasn’t small, it’d be really easy for us to wind up with cervical or uterine infections that made us infertile and very ill. It’s too small for water, but not too small for sperm, which are microscopically teeny-weeny. After ejaculation⁠ (ejaculation: In a sexual context, a discharge of genital fluid, usually (but not always) as a result of sexual stimulation and/or orgasm.) , they head through the vagina, through the cervix and into the uterus, not inside the vagina, seeking out or trying to fertilize an egg. Urine or water from washing can’t get into your uterus.

For more information on how pregnancy happens, check this out: Where DID I Come From? A Refresher Course in Human Reproduction.

If you want to prevent pregnancy and have vaginal intercourse, then you need to use a reliable method of birth control that is highly effective. Condoms are a very easy method for anyone to find, afford and use and when used properly, are very effective. They also protect you from sexually transmitted infections. Other options are female barrier methods – like a diaphragm, which blocks the entrance to the cervix – or hormonal methods – like the birth control pill, which changes your fertility⁠ (fertility: The ability to become pregnant or other things having to do with becoming pregnant (eg, “the fertility clinic”).) cycle continuously so you don’t release eggs to be fertilized, and so it’s tougher for sperm to get to the cervix in the first place. You can talk to your doctor or healthcare provider⁠ (healthcare provider: A qualified person to provide sound physical and/or mental healthcare, such as a doctor, nurse, clinician, counselor, medical assistant, midwife or other healthcare professional.) about any of these methods, and figure out which is best for you.

For a basic rundown of various – real - methods of birth control, have a look right here: Birth Control Bingo!.

And if you or your partner aren’t ready to deal with any method of birth control? Then if you don’t want to become pregnant, the best choice is to not have the kinds of sex that can result in pregnancy until you both ARE ready. For other ways of being sexual⁠ (sexual: About or relating in some way to sex or sexuality.) with a partner, check out NO Pregnancy Risks.