Girls, 22 took PCR. All good, negative on the 25th she got sick. Tempe…

Girls, 22 took PCR. All good, negative on the 25th she got sick. Temperature was 37 with a penny up to 38 it didn't go beyond. A cough and runny nose started. After a couple of days they prescribed medication. In the end, the temperature went away immediately, but the cough and runny nose have been there ever since. On the 29th they took another test for COVID. The test came positive ???? I don't know what to do now. How did he become positive after negative, I haven't gone anywhere...it's just a common cold, no different from ordinary ORV. What should I do ?? give birth day by