So my brother-in-law tested positive for covid yesterday, and I had contact with him on Saturday. I dropped off a nasal swab test for PCR yesterday and it came back negative. However, I started experiencing some symptoms yesterday and still don't feel well (fatigue, nausea, aches and chills). I think it must be a false negative, and I am wondering what the numbers are looking like for this situation?

I know that the antigen tests are not great at detecting omicron in asymptomatic individuals, but I am wondering if even the PCR nasal swabs have had an increase in false negatives with omicron, especially in breakthrough cases. Anyone else have any experience with this? I wonder if the virus just isn't present at high enough levels in my nose, especially since I don't really have any "head cold" like symptoms.