Why did I get a faint positive pregnancy test then a negative?

The weather was sunny. We sat on the sandy beach relaxing after a long week. Every one of us had a glass of mango juice. We wore sexy bikinis as we enjoyed the sun. From a distance, you may have thought we were hired models advertising either mango juice or bikinis. “Is it possible to get a positive pregnancy test then negative?” asked Maria (not her real name). I almost choked after hearing what Maria had just asked. Luckily, we had a doctor amongst us. Jane, not her real name, answered, “Yes! It is possible to have a positive pregnancy test then negative.” I could not believe how the world would be so unfair to us women.

How can I be pregnant this minute and not the next? I was eager to learn how such a disheartening thing would happen so I asked Jane to give more information… The most probable reason for a positive pregnancy test then negative may be because the initial pregnancy test was a false positive. Jane gave the following reasons for a false positive…


  1. It might be due to improper testing
  2. It might be due to evaporation line on a pregnancy test
  3. The use of certain medical conditions
  4. It might be due to defective pregnancy tests

If you conduct an improper testing you’ll get to a false positive result. If you don’t follow the instructions, you’ll not know how the test is supposed to be done, how you should interpret the results, and after what time the result is invalid. Sometimes, we get overexcited, nervous, or anxious when taking a pregnancy test. As a result, we forget to follow the instructions. We don’t remember to take a stopwatch and keep exact time. Thus, we end up reading invalid results.

If you’ve ever taken a pregnancy test, you saw that the urine changes color as it goes across the strip. If you are keen to keep time, you’ll see that a positive result happens when the test changes. If the time elapses, the urine starts evaporating creating a line called the evaporation line. You may confuse this line with a real one and thus read the results as positive instead of negative. Selected medications Some selected medications, for example, phenothiazine can lead to a false positive pregnancy test.

For women undergoing hCG therapy to treat fertility issues or luteal phase defect, they should seek professional medical advice on when to take a pregnancy test. When you have medical conditions like chorio carcinoma and other types of cancer, for example, ovarian, breast and testicular cancer, your urine tends to have hCG. Of course this is not normal because your body is unwell. You know that home pregnancy tests rely on detecting hCG in the urine to show pregnancy. Thus, if you take a home pregnancy test and you’ve not conceived, you’ll get a false positive.

One thing you’ve always known is that both humans and machines are not a 100% perfect. The pregnancy test manufacturers have highly controlled operations. However, things don’t go well always and they may fail to notice a defect in the pregnancy test.

It ends up in the chemist and if you buy and use it, you may get a false positive. As she concluded, she said, “Don’t worry if you get a positive pregnancy test then negative. May be the first pregnancy test was right and the next was not.” The best action is to see a doctor and have a blood test.

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