Implantation bleeding is usually lighter and less consistent than menstrual bleeding. The color of the blood can also help you distinguish between implantation bleeding and your period.

If you’re in limbo, waiting until enough time has passed to take a pregnancy test, you may be looking for early signs of pregnancy.

Implantation bleeding — blood that results when a fertilized egg nestles into your uterine lining — can be one such sign.

Here’s what to expect with implantation, how to chart key points in your menstrual cycle, the best time to take a pregnancy test, and more.

It isn’t always easy to tell the difference between implantation bleeding and an early period.

The following signs may help clue you in to what’s happening:

  • Color. Implantation bleeding is more likely to be a pinky-brown color. Menstrual bleeding, on the other hand, may start off light pink or brown, but it soon changes into crimson red.
  • Consistency. Implantation bleeding is more like on-and-off spotting. Your period, however, starts off lightly and gets progressively heavier.
  • Clotting. If you notice clots in the bleeding, you can be pretty sure that this is your period. Implantation bleeding will not produce this mix of blood and tissue.
  • Cramping. Cramping that signals implantation is often light and short-lived. Cramping that comes from your period is usually more intense and lasts longer.
  • Duration. Implantation bleeding may last 1–3 days while your period may last 3–7 days.

Sometimes timing — in addition to the symptoms above — can help you pinpoint what’s going on. Implantation bleeding happens a bit earlier than when you would expect to get your period.

Let’s walk through the timing, so you can compare dates on your calendar. Day 1 of your menstrual cycle is the first day of your last period.

Ovulation — when one of your ovaries releases an egg to prepare the body for a potential pregnancy — typically occurs in the middle of your overall menstrual cycle.

The average menstrual cycle is 28 days, so ovulation typically occurs around day 14. Menstrual cycles that are shorter or longer than 28 days typically have a different timeline for ovulation.

Although the egg is only viable for about 24 hours, it’s difficult to pinpoint the exact time it’s released into your fallopian tube.

Many healthcare professionals consider the 5 days before suspected ovulation, the day of suspected ovulation, and the day after suspected ovulation to be your window of fertility.

Sperm can live inside your body for up to 5 days, so during this time it’s important to use a condom or other birth control method if you want to prevent pregnancy.

Some birth control works by interfering with sperm’s ability to reach the egg, ultimately reducing the likelihood of fertilization.

Some methods work by thinning the uterine lining so, if fertilization does occur, the egg is less likely to attach to the uterus.

Implantation can only occur if the egg is fertilized and successfully attaches to lining of your uterus. This process can take anywhere from 6–12 days.

If your body follows a 28-day menstrual cycle, implantation may happen between days 20–26. Light spotting that stops around day 28 could be a sign of implantation.

But if your bleeding continues or increases in intensity, it could indicate the onset of menstruation.

Generally speaking, the day you’re expecting your period to start is the best time to take a pregnancy test. If your period is irregular, wait to test until at least 21 days after unprotected sexual activity.

Pregnancy tests measure the level of the hormone human chorionic gonadotropin (hCG) in your blood. Elevated hCG levels are usually a sign of early pregnancy.

Urine pregnancy tests — which can be done at home — are 99% accurate when used as directed. If you receive a negative result and continue to experience unusual symptoms, wait 7 days and retest.

You might also consider getting a blood test to check for pregnancy. Blood tests may be administered a few days earlier than urine tests, so it’s important to consult with a healthcare professional.

Likewise, if your urine test is positive, make an appointment with a clinician to confirm the result. They can administer a blood test and discuss your options for family planning, including adoption and abortion.

Take a look back at your calendar to determine when the first day of your last period was or when sexual activity that could result in pregnancy last occurred.

You might want to jot down the symptoms you’re having and your timeline so you know when it’s appropriate to take a pregnancy test.

If you have any questions or doubts about bleeding that doesn’t seem normal, consult with a healthcare professional to determine next steps.