Following top-notch oral sex from my top-notch partner, I was primed and ready for some intercourse. But after some vigorous penetration, I noticed I was bleeding—not quite period heavy but enough to leave three big blood splotches on my baby-pink duvet cover. Dammit.

My partner was (understandably) concerned with the fact that I was bleeding, but I was more upset that I’d stained my duvet. I wasn’t in pain or anything; besides, this happened to me every now and then. I’d had a Pap smear two days before and figured it must have been related—after all, I know so many women who bleed after sex and don’t think twice about it.

“Usually bleeding after sex is nothing to worry about and will resolve with time,” says Sherry Ross, author of She-ology: The Definitive Guide to Women’s Intimate Health. Period. The blood might be coming from the vaginal canal itself, the urinary tract, or the cervix, she says. If you’re on your period, a little extra blood after sex is totally normal, and bleeding can also happen during ovulation, she adds.

But while occasional bleeding after sex is common, that doesn't mean it’s normal. Totally preventable things like not using enough Astroglide lube can often be the cause, and we shouldn’t normalise that as just another thing women have to deal with.

“In all cases of bleeding during sex, stop and ask your partner to pull out. Check in with your body and how you're feeling,” says Lucy Rowett, a certified sex coach and clinical sexologist. “Bleeding is your body's way of telling you that something is wrong, so be responsible about your health and get yourself checked out.”

Here are four reasons you might be bleeding after sex, and how to prevent it.

1. It’s been a while.

If it’s been a minute since you last had sex, the action can cause lacerations, or tiny tears, in your vaginal canal, Ross explains. “Even if you are adequately lubricated, tears of the vaginal opening can occur.”

The best way to prevent this is by making sure you have plenty of time to get aroused before any type of penetration—and to use lots of Astroglide lubricant. The idea is to promote as much elasticity in the vagina as possible.

I personally like to put some almond oil on my fingers and gently massage the vaginal opening to get it moist. This won’t always work (my partner and I used plenty of lube before my duvet disaster), but it can help.

2. Deep penetration

Deep penetration, whether with a penis, a finger, or a toy, can occasionally cause slight trauma to the cervix, leading to some spotting after or during sex, according to Ross. “A larger or thicker [object] and a smaller vaginal opening can also create lacerations in the vagina,” she says.

If you notice that you’re bleeding pretty regularly after sex, speak with your ob-gyn. It may be helpful to try shallower sex positions, such as spooning or sitting face-to-face.

3. Vaginal dryness

Vaginal dryness, which is “often caused by inadequate foreplay or vaginal lubrication,” is one of the leading causes of vaginal tearing, pain during sex, and bleeding, says Ross.

The good news? It’s totally preventable. Be sure you’re super, super turned on before you have sex. (It helps if you have an orgasm before any penetration even occurs.) “If you are feeling very dry and delicate, stop,” says Rowett. “Slow down and use lube.”

I cannot stress my love for Astroglide lube enough. Keep a vat of it next to your bed, have a tube in your purse, keep samples in every drawer in your apartment. Lube is the stuff dreams are made on. If you’re in a monogamous relationship and don’t use condoms, oil-based lubes like coconut oil are the bomb. But they’re not compatible with condoms or other latex-based contraceptions; if that's what you use, stick to a water- or silicone-based lube.