Implantation bleeding happens when a fertilized egg attaches itself to the lining of the uterus in order to begin growing. It is completely normal and does not need any medical treatment. It’s thought about one third of women experience implantation bleeding. The difficulty is that it happens at a similar time in your cycle to menstruation, so it’s often confused with having an early period.
When does it occur?
When the embryo implants in the uterus, it can disrupt tiny blood vessels in the spot that it attaches. This won’t cause any problems (the endometrium recovers!) but some women will experience light bleeding, from pink to red to brown discharge. Such so-called implantation bleeding will likely arrive earlier than your expected monthly flow (usually around five to ten days after conception).
How to distinguish between bleeding and a period?
Since implantation bleeding often occurs before you test positive on a pregnancy test, it can be hard to know whether light bleeding is an early sign of pregnancy or just normal spotting leading up to your period. And unfortunately, there’s no conclusive test or symptom that will tell you. The best way to know whether you’re pregnant or not is to wait a few more days and take a pregnancy test. The timing of your last intercourse might also help you figure it out: If it’s been more than two weeks, it’s unlikely that any bleeding is due to implantation.
That being said, the approximately one-third of women who report having experienced implantation bleeding often report that it’s distinct from their usual premenstrual spotting — some say the blood is darker and not as red compared with normal period blood. Others have mild cramping at the same time as the spotting. But for many women, the two types of bleeding aren’t different at all. So you’re not alone if you assume that some spotting is implantation bleeding and get your period a few days later, or if you assume that it’s normal spotting and end up being pregnant!
When to see a doctor?
Light bleeding during pregnancy — even at times other than implantation — is often normal. Causes can include mundane things like irritation of the cervix following a pelvic exam or sex or infection of the vagina. But because sometimes bleeding following a positive pregnancy test can be a sign of ectopic pregnancy, molar pregnancy or miscarriage, you should always call your medical provider if you experience bleeding so you can talk through any other symptoms. Don’t worry too much; chances are good that if the bleeding is light and does not last long, everything is fine.
As with a lot of early signs of pregnancy, the only real proof that you’re on the path to parenthood is that all-important line on the pregnancy test. If you think you’ve experienced implantation bleeding, the advice is that you need to wait at least 3 days before taking a home test. Before that, there’s unlikely to be enough of the pregnancy hormone hCG to give a positive result. If you can bear to wait 5 days, there’s even more chance it will be accurate. In the meantime keep looking out for other early signs.