I had covid 4 weeks ago and came out of isolation at the beginning of November. I am double vaccinated. My friend (who I have been in close contact with) has just developed symptoms and has received a positive PCR. I have been notified by test and trace to go and get a PCR test myself. But my original advice was to not get a PCR for 90 days. I now have an annoying cough. How do I find out if I have it again? Is it possible to get it again so quickly? I am very run down and tired at the moment and I didn't get a cough when I originally had covid. Help! Thank you.