Nobody wants to hear it, but it's true: sexually transmitted infections are incredibly common, and even the most careful among us can contract them. Culturally, we are trying to talk about the realities of STIs more often, but there are still a lot of misconceptions out there. If you've heard one of these myths repeated, we're declaring once and for all: it's not true.

1. If you had one, you would know.
Half the human population gets an STI at some point in their life, and a lot of them don't know it. "STIs can fly beneath the radar for months or even years and exhibit no noticeable symptoms," says Dr. Samuel Malloy, co-founder and Medical Director of DrFelix. Chlamydia is the STI most likely to appear without symptoms, yet if left untreated it can lead to infertility, chronic pelvic pain, or pregnancy complications, says Culwell. You can also transmit STIs without having symptoms, so get tested in accordance with the CDC guidelines—whether you notice anything or not.

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2. You need to have sex to get an STI.
Some STIs, like herpes and HPV, can spread through skin-to-skin contact alone, says Culwell. So, you can actually get herpes just from kissing, and while the jury's out on HPV, we do know that you can get either condition through contact with broken skin or any genital-to-genital contact.

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3. The cleaner you are, the less likely you are to get infected.
STI prevention methods like tooth-brushing after oral sex and douchingafter vaginal sex don't work, says Malloy. In fact, excessive cleaning can disrupt your bacterial balance and weaken your immune system.

4. You can only get an STI from another person.
You can actually get an STI from a sex toy, says Malloy, especially if you've used it with a partner. Using dirty sex toys can also lead to skin irritation and other infections, so make sure to clean them after each use.

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5. The location of your herpes tells you what type it is
Despite what many doctors still say, the herpes variants HSV-1 and HSV-2 can either be oral or genital, says sexual health researcher Nicole Prause, PhD. "When oral sex was less common, it was more likely that HSV-1 would be oral and HSV-2 would be genital," she says. "It is still more likely to be type 1 if it is on your mouth and type 2 if it is on your genitals, but these probabilities become more equal every year." In other words, you can't know what type it is without a test.