The Welsh Government has now revised the self-isolation rules.
If you have symptoms of COVID-19, you should self-isolate and take a PCR test as soon as possible.
If you have tested positive for COVID-19 you must self-isolate from the day your symptoms started and for at least 7 full days.
If you test positive, your self-isolation period includes the day your symptoms started (or the day you had the test, if you do not have symptoms) and the next 7 full days. If you get symptoms while you're self-isolating, the 7 days restarts from the day after your symptoms started.
The NHS Wales Test, Trace, Protect service will contact you to give you advice on self-isolation
Self-isolation period
You can leave self-isolation after 7 full days (on day 8 of your self-isolation period).
You should take a lateral flow test (LFT) on day 6 of your self-isolation period and another lateral flow test 24 hours later. This is to check if you remain infectious and could pass COVID-19 on to others.
You should not take a LFT before the sixth day of your self-isolation period because the risks of remaining infectious and the chances of passing it on to others before this period is significantly higher.
If either of the LFTs taken on day 6 or day 7 is positive, you should remain in self-isolation until 2 negative LFTs or day 10 whichever is sooner. A positive result indicates that you are likely to still be infectious and the risk of you passing on coronavirus to others is high. If the result of the LFT test you take on day 6 is positive, wait 24 hours before you take the next test.
If you still have a high temperature after 7 full days, even if the LFT is negative, you should continue to self-isolate until your temperature has returned to normal.
You do not need to continue self-isolating for more than 7 days if you only have a cough or loss of sense of smell or taste. These symptoms can last for several weeks following a COVID-19 infection.