Home pregnancy tests are quite commonly done and there are several types of tests that are carried out. Most of these “at-home pregnancy tests” are dip sticks, which are rather placed into one’s urine stream. The stick is able to detect human chorionic gonadotropin (hCG), a hormone that is produced during early pregnancy.

Some of the pregnancy tests do detect hCG very early in pregnancy. Reputable home pregnancy tests can also indeed be highly accurate, but they are not foolproof. False positives and negatives do occur for a variety of reasons. It is important to remember that once you have a positive pregnancy test, one must consult one’s doctor for prenatal care.

1. Chemical pregnancy

It is possible to have a positive pregnancy test even if one was not technically pregnant. This is referred to as a false positive and is also at times called a chemical pregnancy. A chemical pregnancy does occur in case a fertilized egg, referred to as the embryo, is unable to implant, or even grow rather early. This can occur on account of various reasons.

Early pregnancy loss does not occur because of anything the woman has done. It may be due to issues within one’s uterus, such as fibroids, scar tissue, or a congenital uterine anomaly which does cause the uterus to have an irregular shape.

Lower amounts of certain hormones, such as progesterone, can also reduce the chances of implantation as well as embryo growth.

Some causes of chemical pregnancy are of course unknown.

Chemical pregnancies are indeed thought to be very common, but they typically go rather undetected if a pregnancy test is not taken. These early test results, when wrong, can be emotionally draining. For that reason, it is recommended that you can wait to use an at-home pregnancy test until one week after one expected one’s period to start.

2. Ectopic pregnancy

Sometimes a fertilized egg can indeed implant itself outside of the main cavity of the uterus. This does cause an ectopic pregnancy to occur. Ectopic pregnancies usually do happen if a fertilized egg gets stuck in a fallopian tube during its process towards one’s uterus. This can also happen if the tube has scar tissue. This type of ectopic pregnancy is also referred to as a tubal pregnancy.

Ectopic pregnancies do occur in the cervix, ovary, or abdominal cavity.

An ectopic pregnancy cannot indeed turn out to be a normal pregnancy. The embryo is not viable on account of the fact that there is no place for it to grow or thrive outside of one’s uterus.

The embryo will continue to produce hCG, even though it has been implanted in the wrong place. That can rather cause a false-positive reading on an at-home pregnancy test.

Ectopic pregnancies are no doubt medical emergencies. Ectopic pregnancies can be rather damaging to the woman if left untreated, thus causing extreme blood loss or even loss of the reproductive organs. Symptoms of ectopic pregnancy include:

• nausea and sore breasts, which are also symptoms of a normal pregnancy
• sharp waves of pain in the abdomen, pelvis, shoulder, or neck
• severe pain on one side of the abdomen
• light to heavy vaginal spotting or bleeding
• dizziness or fainting
• pressure on your rectum

Seek immediate medical help if one does suspect an ectopic pregnancy.

3. Recent miscarriage or abortion

One may continue to test positive for pregnancy thus following the loss of a pregnancy, either through miscarriage or abortion. During pregnancy, hCG levels do continue to rise as the placenta grows, doubling rather every few days and also peaking at around 10 weeks. When a pregnancy ends, hCG levels do begin to recede but is a rather slow process. The hormone can remain in one’s blood and urine for up to six weeks following the loss of one’s pregnancy. It is possible to have a false-positive test until one’s hCG levels return to their pre-pregnancy state.

If the miscarriage happened to be spontaneous, it is also possible that not all of the pregnancy-related tissue was rather eliminated. This will indeed cause hCG levels to remain elevated. When this occurs, a minor surgical procedure referred to as a dilation and curettage are often required in order to remove the tissue.

4. User error

At-home pregnancy tests are not foolproof. One must follow package directions exactly and also check the expiration date prior to use. Even with these safeguards, user error can also occur. One of the most common mistakes is also taking the test too early during one’s cycle. This can also cause either a false negative or even a false positive.

It is also important to use the test when one’s urine is not diluted excessively with water and is also very concentrated, like when one wakes up in the morning.

Leaving the dipstick in one’s urine stream for the exact amount of time allotted is also very important. Make use of a timer or a stopwatch or one’s phone. That can help one to track how long the dipstick has been in one’s urine stream. One will like to make use of the timer again while one is waiting for the results. Checking the results during the result time frame is considered to be important.

5. Evaporation lines

Sometimes an evaporation line can be rather mistaken for a positive pregnancy test. Some at-home tests do show two lines when hCG is detected and one line when hCG is not actually detected. The lines are usually a bright color, such as pink, red, or blue. Sometimes, a faint-colored second line will also appear. This line may represent an early pregnancy or it may be an evaporation line. It is also probably an evaporation line if the line is completely colorless.

Evaporation lines may also show up on a test if one view after one’s urine has evaporated completely. Sometimes they occur due to hormonal levels which do not represent pregnancy. The best way to avoid being confused is by an evaporation line that does follow the timings of the test directions exactly as they are actually given.

6. Medications

If one is trying to become pregnant under a doctor’s care, one may be taking fertility medications. The hCG shot does help the follicles release mature eggs. It may cause a false-positive reading on an at-home pregnancy test, particularly if the test is done too early.

Other medications that can cause false-positive pregnancy tests are:

• antianxiety medications, like diazepam (Valium) or alprazolam (Xanax)
• Parkinson’s disease medications, including bromocriptine (Parlodel
• antipsychotics, like clozapine or chlorpromazine
• anticonvulsants, such as phenobarbital or other barbiturates
• diuretics, such as furosemide (Lasix, Diuscreen)
• antihistamines, which include promethazine
• methadone (Dolophine)

7. Certain medical conditions

Rarely, certain medical conditions do cause a home pregnancy test in order to give a false positive. These do include:

• a urinary tract infection
• kidney disease that does causes blood or white blood cells in one’s urine
• ovarian cysts, particularly corpus luteum cysts
• more serious diseases like ovarian cancer
• pituitary problems which are rare