Anyone had a negative PCR followed by a positive one?

[dontdoitlikethatdoitlikethis]

DS12 came out of school on Tuesday feeling awful with sore throat, headache, snotty nose and fatigue. He was fine in the morning before school so this was sudden development.

I did LFT on him = negative and a day one PCR where he swabbed his own throat and nose; negative.

The school wrote yesterday to say that Covid is "prevelant" in his yeargroup : it transpired that a quarter of his class were off on Tuesday with confirmed or suspected Covid. Their symptoms are the same as my son's and he was sitting next to confirmed cases at the end of last week.

I am CEV and have been isolating him in the house. The day one PCR coming back negative should be a relief but to be honest my first thought was "I don't think I believe it".

Has anyone had a PCR come back negative on day one of symptoms but show up positive later on? If so by which day did it become positive please?

DS is now on day 3. He still has all symptoms and slept all day yesterday. I understand there are other viruses around but the prevalence of the Covid virus in his yeargroup plus his symptoms matching those reported on the Zoe app for Delta match mean I'm
worried it's covid.

Many thanks

It could just have been too early. Maybe do another PCR just in case

Yes. I did a test on Sunday (negative) and repeated it on Thursday (positive). I had a cough and headache for the first test and had lost my sense of smell by the Wednesday which indicated I needed another test.

Yes my sister’s family all did PCR as one of her children had it. All PCR except that one child were negative but then another of her children tested positive a couple of days later and had symptoms just like your DS.

Yes, happened here. DD2 didn't test positive until she'd had symptoms for a week. Apparently false negatives are common with lateral flow tests because there's a fairly small time window where this test identifies a positive infection. False positives are, conversely, very rare.

My dd tested negative on LFTs until he was quite ill and then his PCR came through positive and his LFT (which he did to see if they worked) came back as clear as day! He’s nearly out of isolation but looks like more of us could test positive 😷 in the family

Yep. DD1 did a pcr sunday as advised as DD2 tested positive on saturday. Came back negative. By tuesday evening, she tested positive on a LFT and did a PCR wednesday morning which was also positive. We knew taking the PCR sunday was too early, but test and traceninsisted we had one done asap