Can I have sex while taking Vaginal Lutein?

Yes, you can have sex with Lutein vaginal tablets. I am attaching a study that may be helpful: https://www.gdziepolek.pl/artykuly/jak-stosowac-preparaty-ginekologiczne

Up to @Mona: According to the medicine documentation, vulvovaginal disorders such as discomfort, burning, vaginal discharge, dryness and vaginal bleeding have been seen in 1.5% of patients taking Lutein.

Is it normal that when using Lutein I feel discophon during intercourse?

The pregnancy test should be done on the day of the expected menstruation or 14 days after intercourse.

And can I do a pregnancy test tomorrow or is it better to wait another time?

Yes, it is positive.

But the first one is positive what I sent you

The test is negative.

This company

What company is this test? Instructions for reading the test should be on the packaging.

Is this test negative

This test was done on Sunday and on Tuesday I already had a negative test.

It may or may not be.

And whether the spotting I had now for 3 days can indicate that fertilization took place

According to the manufacturer of the ovulation test: "Positive result: A positive test result is indicated by two distinct stripes both in test zone T and in control zone C. Typically, the intensity of the T-strip will be the same or stronger than the intensity of the color of the stripE C." Your result is positive.