This is a very common question. Many people who are late, but begin bleeding before taking a pregnancy test, or have a negative test, assume that they were pregnant and miscarried. The “evidence” for this piles up when the cramps are stronger, there is more blood, and maybe even clots are passed.

Miscarried-or-not-pregnant

Most likely, this was not a miscarriage. Remember that light bleeding is common in pregnancy and may not signal the end if it stops shortly after it starts. See symptoms for more information. If you have had a positive pregnancy test, this information is not for you. There is no doubt you were pregnant. Go the the miscarriage diagnosis section instead.
One important note: If your blood type is Rh negative (such as O negative, A negative, B negative, or AB negative), you MUST have a shot to prevent building antibodies after a miscarriage if the father was Rh positive. If you even suspect a miscarriage, find out your blood type and see a doctor right away (within 72 hours) to determine if you need the shot to protect your future pregnancies.

Here’s some information that might help you understand unusual periods that are not miscarriages, especially if you had a negative pregnancy test:

  • But my period was so heavy and painful.

Any late period is going to be heavy.

A late period is caused by extra time being added to the first half of the cycle, which is when the lining is being built. If more lining is built, it will cause more blood flow and stronger cramps to get it out. Blood clots are a natural part of any lining that has had to hang around longer than intended. Late periods are often caused by illness, stress, serious physical exertion, or hormone changes.

  • But I timed intercourse just right, and my period came early.

An early period is almost never a miscarriage.

An early period is often caused by a lack of ovulation, or the ovulation of an egg that is not able to be fertilized. As a result, progesterone is not produced sufficiently to keep the last part of your cycle going. In this situation, a pregnancy cannot happen. Even a positive ovulation test does not mean your ovulation will surely happen or will produce a quality egg. If you are charting your temperatures, however, and see that you did not have at least 10 days between ovulation and when your periods began, you may have a luteal phase defect. Read more about it.

But I saw some tissue that must have been a pregnancy.

A baby from a pregnancy that made your period less than two weeks late is not usually visible to the naked eye.

Even if the baby had grown, it would be about the size of a grain of rice. This would be impossible to see amongst the blood and clots. What you are seeing may be part of a pregnancy, but is more likely just clots and uterine lining from an off-month cycle.

  • But I got this huge golf-ball sized clot I’ve never seen before. It had to be a baby.

Tissue that is like a ball is often what is called a corpus luteum cyst, and not a baby.

An extra long or extra short period can be caused when the shell that once housed the egg (called the corpus luteum) swells in size and throws off the hormone chain. This ball will come out in the period, leaving many women to believe they were pregnant, when actually they had a non-viable egg that month.
Without a positive pregnancy test, it is impossible to know for sure if you were pregnant. If you are actively trying to get pregnant, and have had several suspicious periods, then it is time to get tested for a luteal phase defect. You may indeed be losing babies due to low progesterone.

One way to possibly find out is get to the doctor immediately when you think you are pregnant but start bleeding heavily (do not wait, even a day or two) and have a quantitative hCG blood pregnancy test done. Any hCG in your system would show that you were at one point pregnant. Otherwise, unless your blood type is Rh negative, you should not need to worry about a lost pregnancy.