- The study was conducted too early, when the level of hCG in the urine is low;
- the test strip has expired;
- a large amount of liquid, drunk the day before, decreased the concentration of hormones in the urine.
Reasons for positive false results:
- taking hormonal drugs with hCG;
- the presence of a malignant tumor on the internal genitalia;
- less than 3 weeks after a spontaneous or medical abortion.
Principle of the pregnancy test
Any such test is recognized in the urine of a womanpresence of a special hormone hCG. This is human chorionic gonadotropin, which begins to develop from the beginning of pregnancy, and gradually its amount increases. After attaching the fetal egg to the wall in the uterine cavity, the hCG level begins to increase twofold every two days and increases by 12 weeks as much as possible. After an abortion or a safe pregnancy, hCG reveals its presence in the urine and blood of a woman for three weeks. This should be taken into account for women who have spontaneous abortions, but they hope to preserve the fetus or, conversely, fear that part of the egg has remained in the uterine cavity. The time when it is best to conduct testing The time of the day when to do a pregnancy test is recommended by the manufacturer. It all depends on the type of test and its sensitivity. If you carefully read the instructions attached to the test strip, then there is written the time. Inkjet tests with a mark of 10 mMе / ml have a high degree of sensitivity, and the time of collection of urine for them has no significant difference. After the urine hit the sensitive part of the strip, a reaction begins that will show the result whether the woman is pregnant or not. The day when to do testing To determine whether a woman is pregnant with a strip test at home, you need to wait for the first day of the proposed menstruation. If the discharge does not begin, then on the first day of the delay, you can determine if the egg was fertilized or not. The sensitivity of tests for the presence of hCG also plays a role in this process. If you buy a test strip in the pharmacy with a sensitivity of 20-25 mMe / ml, then he will be able to determine the presence of an embryo in the uterine cavity from the first day of the delay. More sensitive with 10 mMe / ml, more expensive tests, can determine whether a conception occurred, a week after when the supposed fertilization of the egg was supposed to occur. If a week has passed from the supposed monthly, which has not started, you can buy a test of any sensitivity. Its result will be correct. A blood test for HCG one week after the alleged conception on a paid basis can be done in a female consultation. Testing is carried out in the laboratory of the IVF clinic, in the centers of medical diagnostics. 
What are the tests for pregnancy, and how to use them
In drugstores you can buy strip tests, ortest strips. This is one of the most common tests that women buy when they need to determine if the egg has fertilized. The strip is lowered to the desired mark in a jar with morning urine. Hold there for a few seconds, then pull out and put on a flat surface. After a while, you can pick up a strip and look at the result. All types of tests have the same principle: one strip - there is no pregnancy, two strips - it is. If the test shows a negative result, do not throw the strip into the bucket. Lay it until evening on a flat surface. Very often, the reaction is slower than a woman wants, or hCG is still a little in the urine. Practice shows that the second strip can appear in a weak form and later. This means that the pregnancy has come. If you test again, a week later the strip will become much brighter. Tablet tests are arranged according to the same principle as the strip tests. The difference is that the test strip is enclosed in a tablet. To conduct the test in the middle, morning urine drips and after a while they look at the result. Inkjet tests refer to sensitive tests. They are convenient in that they simply substitute under the jet of urine, at any time of the day or night, a little wait and watch the result. Which pregnancy test to choose The choice of test depends on how many days have passed from the alleged conception and personal sensations. Sometimes a woman a week after conception knows for sure that she is pregnant. Sometimes he does not suspect about the occurred conception, until the delay in menstruation tells her that some changes occur with her body. If the delay is high, then there is no point in choosing a particular test in the pharmacy. Pregnancy will show any of them. If you really want to determine, but it took a little over a week, you need to buy a sensitive pregnancy test and satisfy your curiosity. You can go to the laboratory and get tested for hCG, which will be 100% accurate. Ectopic pregnancy and testing Ectopic pregnancy is also determined by a strip test. If at 7-8 weeks after conception the woman felt pains in the abdomen, bleeding began, immediately it is necessary to call an ambulance. Caution should pain of drawing character and spotting with a positive result. It is necessary to contact the doctor-gynecologist in advance to exclude an ectopic pregnancy. A woman's awareness of pregnancy in the early stages gives her the opportunity to plan her future life, become registered in a women's consultation, take all tests and bear a child to become a mother.
