Is it implantation bleeding or your period? Here’s how to tell the difference

If you notice spotting or light bleeding before you’ve even taken a pregnancy test, it can be confusing: Could this be implantation bleeding or just the sign of an impending period?

When I was trying to conceive my third baby, I noticed tiny pink drops of blood on toilet paper a few days before my expected menstrual cycle. I was worried—was my period coming early? Since I was still in the middle of my two-week wait before taking a pregnancy test, I resolved to just ignore it. The bleeding stopped that evening, and a few days later, I found out I was pregnant! My OB-GYN described what I experienced as implantation bleeding, which is a less common sign of early pregnancy.

Vaginal bleeding is common in the first trimester of pregnancy, with 1 in every 4 women experiencing the phenomenon. Implantation bleeding is one type that usually occurs 7 to 14 days after conception when a fertilized egg attaches to the interior lining of the uterus. Since most pregnancy tests aren’t 99% accurate until the day of your missed period (which is about 12 to 16 days after ovulation, depending on your cycle), it’s possible to have bleeding or spotting before getting a positive pregnancy test.

Early bleeding can take you on a roller coaster of emotions. Below, we’ve broken down everything you need to know about implantation bleeding, including potentially dangerous signs of early bleeding to be aware of.

What are the different types of bleeding?

Implantation bleeding is a somewhat common early pregnancy symptom that occurs in 15% to 25% of pregnancies. However, it is just one type of bleeding a woman may experience during her monthly cycle, whether she is pregnant or not.

There are several ways to distinguish implantation bleeding from your regular menstrual bleeding.

Signs of implantation bleeding:

• Light pink to dark brown in color
• Doesn’t contain clots
• Light discharge, usually just seen when wiping or a few drops on a panty liner
• Intermittent or a constant light flow that stops on its own

Signs of normal menstrual bleeding:

• Bright or dark red
• Can include clotting
• Can be light or heavy
• Can cause pain and cramping
• Fills tampons and pads
• Lasts two to seven days

Because blood vessels are developing rapidly in the cervix during pregnancy, it may be more prone to light bleeding. Pregnant people may also experience light bleeding from irritation of the cervix after a pelvic exam, bleeding from irritation or small tears occurring during sexual intercourse, bleeding after heavy lifting or exertion, or bleeding from a vaginal infection. Light bleeding may also occur during ovulation.

How can I tell if I have implantation bleeding?

If you’re wondering if you may be experiencing implantation bleeding, the first step is to look at the timeline in the two weeks between ovulation and a positive pregnancy test.

• Ovulation: Usually occurs around day 14 of your menstrual cycle, with day 1 being the first day of your last menstrual period.
• Fertilization: The egg meets the sperm around 24 to 48 hours after ovulation.
• Implantation: A fertilized egg known as a blastocyst will then make its way down the fallopian tube to the uterus and implant itself into the uterine lining. This occurs 6 to 12 days after ovulation, or around days 20 to 26 of your menstrual cycle.
• Positive test: The hormone hCG rises enough to be detected on a positive pregnancy test 10 to 14 days after ovulation.  

If bleeding occurs 6 to 12 days after ovulation, during the time of implantation, this is the first sign you could be experiencing implantation bleeding.

Implantation bleeding can also accompany other early pregnancy signs:

• Food cravings or aversions
• Breast changes
• Increased urination
• Fatigue
• Nausea
• Raised basal body temperature
• Dizziness

Related: 9 early signs of pregnancy before a missed period

Complications related to implantation bleeding

While implantation is a normal experience with no causes for concern, other early bleeding could be a sign of complications.

First-trimester bleeding can be caused by implantation bleeding, spontaneous abortions, ectopic pregnancy and lesions involving the female reproductive system and perineal area infections. 

It could also be a sign of an early miscarriage or a chemical pregnancy, which is an early pregnancy loss that occurs shortly after implantation and accounts for 50% to 75% of all miscarriages. 

You should always talk to your doctor if you have any concerns about first-trimester bleeding to rule out any potential complications.

Related: What month will my baby be born? Here’s how to calculate your due date

A note from Motherly on implantation bleeding

Although it can be worrying to see blood when you are trying to conceive, it doesn’t always mean something is wrong. Many women with vaginal bleeding in very early pregnancy go on to have successful pregnancies. Miscarriage usually only occurs in half of women who bleed in the first trimester. In fact, implantation bleeding could be your first sign that you are pregnant! Your best course of action is to take a pregnancy test, watch and wait for symptoms to resolve and talk to your doctor about any concerns.

Sources

Deutchman M, Tubay AT, Turok D. First trimester bleeding. Am Fam Physician. 2009 Jun 1;79(11):985-94. 

Dumitrascu MC, Iliescu M, Petca RC, Sandru F, Mehedintu C, Farcasanu PD, Maru N, Chibelean C, Petca A. The Chemical Pregnancy. Rev. Chim. 2019 Nov;70(11):3818-3823. doi:10.37358/RC.70.19.11.7652

Harville EW, Wilcox AJ, Baird DD, Weinberg CR. Vaginal bleeding in very early pregnancy. Hum Reprod. 2003 Sep;18(9):1944-7. doi: 10.1093/humrep/deg379. 

Promes SB, Nobay F. Pitfalls in first-trimester bleeding. Emerg Med Clin North Am. 2010 Feb;28(1):219-34, x. doi: 10.1016/j.emc.2009.10.005. 

A version of this story was originally published on Dec. 22, 2021. It has been updated.