How To Tell If You Have Implantation Bleeding Or Your Period

Photographed by Ashley Armitage.
If you're not trying to get pregnant, and are worried that you might be, then seeing blood in your underwear can feel somewhat reassuring. Bleeding means you have your period, which means you're not pregnant, right? Not necessarily, because there's always a chance that you're experiencing implantation bleeding, which means the exact opposite: pregnancy. That's why anyone trying to conceive might actually feel a surge of hopefulness at the sight of a little blood.
When a fertilized egg is in the process of attaching to the uterine lining, sometimes it can cause light bleeding, also known as "implantation bleeding," says Raquel B. Dardik, MD, an Ob/Gyn at NYU Langone Medical Center. During implantation, it's almost as if the embryo is "trying to burrow into the uterus," so it's normal to have some spotting, Carolyn Alexander, MD of the Southern California Reproductive Center told Refinery29 last year.
It's easy, at first, to confuse implantation bleeding with your period. Hey, hoping to be pregnant and hoping to NOT be pregnant can both be pretty intense situations. Rather than losing it over a little blood, learn to spot the difference between the two, so you'll know right off the bat what you're dealing with.
In general, implantation bleeding tends to be spotty and light, not necessarily flowing like a period, Dr. Dardik says. The blood itself is usually pink to light brown, she says. Some people say that it kind of looks like rust, and doesn't look like their typical period blood. But implantation bleeding can happen near the time that you get your period, which causes some people to think it's just an early flow, Dr. Dardik says.
Often, the timing can actually indicate whether you have implantation bleeding or your period. A fertilized egg typically implants about 10 days after ovulation, Dr. Dardik says. "So, on a 28-day cycle, you would ovulate on day 14, implant on day 24, and skip your period on day 28," she says. That is, it could be implantation bleeding if it's happening a few days before you expect to get your period. "This assumes you are very regular," she says. "If you have cycles that tend to vary in length, even by a few days, it may seem to happen when you anticipate your period." So you can see why this could get confusing.
Implantation bleeding can last a few hours or a few days, according to the American Pregnancy Association. The bleeding will go away on its own, and you don't really have to do anything when it happens — although it might be a good time to take a look at your calendar or pill pack and figure out where you are in your cycle, to see if it might just be an early period. Really, the only way to know whether you are pregnant or not is to take a test.
Of course, you'll have to wait a few days for an accurate read. After a fertilized egg implants, the placenta forms and produces a hormone called human chorionic gonadotropin (hCG), which is what pregnancy tests are looking for, according to the Mayo Clinic. HCG enters the bloodstream first and then moves into urine, so that's why you pee on a pregnancy test. For an ASAP answer as to what's going on, head to your doctor for a blood pregnancy test. Otherwise, wait a few days until you expect your period to arrive and, if it doesn't, test then.
If you are trying to get pregnant, paying attention to symptoms like implantation bleeding can later help you and your Ob figure out exactly how far along you are (romantically keeping tabs on the dates you've had sex helps with this, too). If you already know you are pregnant, and are experiencing light bleeding, it's a good idea to talk to your doctor. Some spotting early in pregnancy is usually not a big deal, and happens to 15 to 20% of people during the first trimester, according to the American Congress of Obstetrics and Gynecology. But heavier bleeding, or bleeding later in pregnancy can be a sign of something more serious.
Essentially, keep an eye on what's in your underwear, because different types of bleeding at different times during your cycle can mean very different things — whether you're pregnant, or want to be, or not.
Welcome to Mothership: Parenting stories you actually want to read, whether you're thinking about kids or not, from egg-freezing to taking home baby and beyond. Because motherhood is a big if — not when — and it's time we talked about it that way.

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