Could attempted penetration without protection cause pregnancy for first-time partners?

Getting a P-test as negative with irregular menses and movements in the stomach with this information the chances of being pregnant cannot be ruled out.

Most important factor associated with P-test is when and how it is being performed.

False Negative Pregnancy Test

- A false negative pregnancy test is in case you are pregnant but the test comes up negative. The most common reason behind false negative is that the test was performed too early.

Even though your period is late as per your usual cycle, you might have ovulated later in the month. It's not unusual to have an off or irregular cycle occasionally. In addition to it, you must have counted the number of days from your last period incorrectly

Pregnancy tests assess the pregnancy hormone hCG, which rises as pregnancy progresses. The standard range for hCG levels in pregnant women may differ. Pregnancy test before the specified time might pick and detect low amounts of hCG.

-Another reason behind the false negative is not having sufficient hCG in the urine while performing the test.  In the early days of pregnancy, there is chance that the hormone concentration can get diluted in case you consume a large amount of water before testing.

The hCG concentration is on the higher side in case you have hold the urine for long time and that is why it is recommended that you should take a pregnancy test in the morning.