Will the result of the pregnancy test after 3 weeks after intercourse be reliable?

The result of the pregnancy test after 3 weeks of intercourse is already reliable and a negative result means that you are not pregnant. Getting an infection and using an antibiotic can delay menstruation. I also attach a link to the article in which we describe what may be the causes of menstrual disorders: https://www.gdziepolek.pl/kategorie/leki-na-zaburzenia-miesiaczkowania

I had interrupted sexual intercourse, after it there was a delay of 6 days and after the delay menstruation began. Also, a month later, without delay, I began to menstruate again. But I was worried about pregnancy, so I did 2 pregnancy tests 3 weeks after intercourse and 4 weeks after intercourse. Are the tests reliable? And is it possible that menstruation can be during pregnancy?

To @❤️❤️❤️:
Delaying menstruation by 8 days, especially after intercourse during ovulation, can raise suspicions of pregnancy, especially if unusual symptoms such as changes in the breasts or irritability to smells appear.

A negative pregnancy test on day 4 of delay may still be done too early, as the level of pregnancy hormone (hCG) may not be high enough to detect it. It is worth repeating the test after a few days or going to the doctor for a blood test, which is more sensitive. Abdominal pain and frequent urination can also indicate other causes, such as an infection, so it's a good idea to consult a doctor if symptoms persist.

Please tell me if this can be pregnancy, a delay of 8 days, sexual intercourse was 2 weeks ago on the last day of ovulation, the breasts do not hurt as always, before menstruation it became very soft, the smells are irritating, there is no fatigue and I often go to the toilet and my stomach aches almost constantly! The test was negative on the 4th day of the delay.

We had 2 sexual intercourse with a two-bedroom girl, because of which we are worried, the difference between them is 7 days, we were prevented, but I was worried about the quality of the condom, the first sexual intercourse was on the 31st and the second was already on the 7th, because of the second sexual intercourse I was worried most of all, as I found a small hole with the size of a needle and after 30-40 hours we drank extra contraceptives, then on the 14th she had her period (the cycle did not go astray, everything was normal) we did the test after the first act after 11-12 days in the afternoon and the test was negative, then they did it a month after the 2nd sexual intercourse, the test was done after 2 hours after she woke up and the test was also negative, but at the same time she sometimes feels sick in the morning not very often about 3-4 times a week and has a headache, The rest, according to her, everything is fine, do we need to worry about anything further?

To @Ewaa:

You can rule out pregnancy.

Three weeks ago I had sex with my husband and the condom broke. I did the first test two weeks after intercourse (negative), the second one I did after another week, i.e. three weeks after intercourse and it is also negative. Both tests were of high sensitivity, but I did them in the afternoon. Can I consider them credible?
I would like to add that I am breastfeeding and I have not yet had my period since the birth (6 months after the birth).

To @Kami:

You probably took the test too quickly. Please repeat after min. 10 days after intercourse.

Hello, I'm 37 years old and I had intercourse with my husband in ovulation, I did the test and it is negative, did I do it too soon, I had intercourse on May 1 and the test was done 4 days after ovulation

Hello. Please tell me, on this test I see the second streak is very weak and gray. Today is the fifth day of the delay, a month has passed even a little more since sexual intercourse. Help identify the pancreas.

To @12345: Yes, the result is reliable.

Today I repeated the test (28 days after intercourse) from morning urine, with a sensitivity of 10 and also negative. Is the result already reliable?

To @12345: With proper use of birth control pills, the likelihood of pregnancy is negligible. These symptoms, as well as the pregnancy test, also do not indicate pregnancy. There is no need to worry and I do not see the need to repeat the test.

I've been taking atywia daily since January. For the first 2/3 weeks I took at 18:30, then I started taking in the range of 20-23. I'm at pack 3, in a week I should start taking placebo pills. On February 10, there was intercourse, without protection. On February 18, after 2 placebo tablets I got 2 days of heavy bleeding, on the 3rd day there was almost no bleeding, I started a new blister. For about a week I have severe abdominal pains radiating to the back, there is also a yellow thick mucus. Does ro indicate pregnancy? I took the pregnancy test on day 22 from intercourse with sensitivity of 10 and it came out negative. Is there a need to repeat the test?

Up to @Czarna: Negative results of pregnancy tests performed 10, 14 and 20 days after intercourse are reliable. Usually, pregnancy symptoms are felt only a few (4-6) weeks after fertilization.