When should you take a pregnancy test with irregular periods

Q: How do I know if Im pregnant with irregular periods?

You can tell if youre pregnant even if you have irregular periods with signs of pregnancy other than a missed period, such as implantation bleeding, nausea, swollen or tender breasts, fatigue, frequent urination, mood swings, headaches, backaches, and changes in cravings or aversions.

What does this test do? This is a home-use test kit to measure human chorionic gonadotropin (hCG) in your urine. You produce this hormone only when you are pregnant.

Table of Contents Show

How do pregnancy tests work?
How accurate are pregnancy tests?
How soon can I take a pregnancy test?
Where can I get a pregnancy test?
What should I do if my pregnancy test is positive?
More questions from patients:
How do I know if I'm pregnant with irregular periods?
Do pregnancy tests work if you have irregular periods?
When should I take a pregnancy test with irregular periods and PCOS?

What is hCG? hCG is a hormone produced by your placenta when you are pregnant. It appears shortly after the embryo attaches to the wall of the uterus. If you are pregnant, this hormone increases very rapidly. If you have a 28 day menstrual cycle, you can detect hCG in your urine 12-15 days after ovulation.

What type of test is this? This is a qualitative test -- you find out whether or not you have elevated hCG levels indicating that you are pregnant.

Why should you do this test? You should use this test to find out if you are pregnant.

How accurate is this test? The accuracy of this test depends on how well you follow the instructions and interpret the results. If you mishandle or misunderstand the test kit, you may get poor results.

Most pregnancy tests have about the same ability to detect hCG, but their ability to show whether or not you are pregnant depends on how much hCG you are producing. If you test too early in your cycle or too close to the time you became pregnant, your placenta may not have had enough time to produce hCG. This would mean that you are pregnant but you got a negative test result.

Because many women have irregular periods, and women may miscalculate when their period is due, 10 to 20 pregnant women out of every 100 will not detect their pregnancy on the first day of their missed period.

How do you do this test? For most home pregnancy tests, you either hold a test strip in your urine stream or you collect your urine in a cup and dip your test strip into the cup. If you are pregnant, most test strips produce a colored line, but this will depend on the brand you purchased. Read the instructions for the test you bought and follow them carefully. Make sure you know how to get good results. The test usually takes only about 5 minutes.

The different tests for sale vary in their abilities to detect low levels of hCG. For the most reliable results, test 1-2 weeks after you miss your period. There are some tests for sale that are sensitive enough to show you are pregnant before you miss your period.

You can improve your chances for an accurate result by using your first morning urine for the test. If you are pregnant, it will have more hCG in it than later urines. If you think you are pregnant, but your first test was negative, you can take the test again after several days. Since the amount of hCG increases rapidly when you are pregnant, you may get a positive test on later days. Some test kits come with more than one test in them to allow you to repeat the test.

Is this test similar to the one my doctor uses? The home pregnancy test and the test your doctor uses are similar in their abilities to detect hCG, however your doctor is probably more experienced in running the test. If you produce only a small amount of hCG, your doctor may not be able to detect it any better than you could. Your doctor may also use a blood test to see if you are pregnant. Finally, your doctor may have more information about you from your history, physical exam, and other tests that may give a more reliable result.

Does a positive test mean you are pregnant? Usually, yes, but you must be sure to read and interpret the results correctly.

Do negative test results mean that you are not pregnant? No, there are several reasons why you could receive false negative test results. If you tested too early in your cycle, your placenta may not have had time to produce enough hCG for the test to detect. Or, you may not have waited long enough before you took this test.

If you have a negative result, you would be wise to consider this a tentative finding. You should not use medications and should consider avoiding potentially harmful behaviors, such as smoking or drinking alcohol, until you have greater certainty that you are not pregnant.

You will probably recognize incorrect results with the passage of time. You may detect false negatives by the unexpected onset of menses (regular vaginal bleeding associated with “periods”.) Repeat testing and/or other investigations such as ultrasound may provide corrected results.

How do pregnancy tests work?

Pregnancy tests are an easy and accurate way to find out if you’re pregnant — you just pee on a stick. They’re inexpensive and available at most drug and grocery stores.

How accurate are pregnancy tests?

Pregnancy tests are super accurate when you use them correctly. The pregnancy tests you get at the drugstore work 99 out of 100 times. They’re just as accurate as a urine pregnancy test that you’d get at a doctor’s office.

Pregnancy tests work by checking your urine (pee) for a hormone called human chorionic gonadotropin (HCG). Your body only makes this hormone if you’re pregnant. HCG is released when a fertilized egg attaches to the lining of your uterus — when pregnancy begins. If your pregnancy test results are positive, it means you're pregnant. If they’re negative, it means you’re not pregnant.

Pregnancy tests are most accurate when you take them after you’ve already missed your period.

A pregnancy test will be less accurate if it’s expired or if you don’t use it the right way. So always check the expiration date on the package, and carefully read the directions that come with your pregnancy test.

How soon can I take a pregnancy test?

You can take a pregnancy test anytime after your period is late — that’s when they work the best. It’s a good idea to take a pregnancy test as soon as possible if you miss your period or think you might be pregnant.

The earlier you know you’re pregnant, the sooner you can start thinking about your options and get whatever care you need to stay healthy.

Many pregnancy tests say they work a few days before a missed period, but the results are usually less accurate then. Read the label on your pregnancy test to find out when to take a pregnancy test and how accurate it’ll be.

Sometimes a pregnancy test is able to find pregnancy hormones in your urine as early as 10 days after unprotected sex. But these results aren’t super reliable, and you may get a false positive or false negative test result.

If your periods are very irregular, or you don’t get periods at all for one reason or another, your best bet for accurate results is to take a pregnancy test 3 weeks after sex.

Where can I get a pregnancy test?

You can buy a pregnancy test at your local pharmacy, drugstore, grocery store, and some convenience or dollar stores. Pregnancy tests are usually inexpensive — they can cost as little as a dollar. Sometimes you can get a free pregnancy test at certain health centers.

You can also get a pregnancy test from your nurse or doctor, community clinic, or local Planned Parenthood Health Center. Most health centers use the same urine pregnancy tests that you can buy in stores. Sometimes they use a blood test to test for pregnancy, but that’s usually only under special circumstances.

But be careful when looking for a reliable health center, because there are fake clinics out there called Crisis Pregnancy Centers. Crisis Pregnancy Centers give free pregnancy tests and claim to offer information and help. But they’re run by people who may not be medical professionals, and don’t believe in giving you honest facts about pregnancy and all of your options. Crisis pregnancy centers are often located very close to Planned Parenthood health centers or other real medical centers, and have similar names — they do this to confuse people and trick them into visiting their center instead.

Your nearest Planned Parenthood health center can help you find a safe place to get a pregnancy test in your area.

What should I do if my pregnancy test is positive?

If you take a pregnancy test after you miss your period and the result is positive, that means you’re pregnant. You can always take another test to be sure, if you want.

You may want to go to a nurse or doctor, family planning clinic, or local Planned Parenthood Health Center to get a follow-up test. They’ll talk with you about your pregnancy options, and help get you the care you need. Be careful not to visit a Crisis Pregnancy Center, because they might not give you real medical care or truthful information about your pregnancy and all of your options.