Do asymptomatic people cause covid 19 ? and is incubation period if covid 19 only 7 days or full 14 days. ? please help

COVID-19 Incubation: On average, the time from exposure to symptom onset (known as the incubation period) is about five to six days. However, studies have shown that symptoms could appear as soon as three days after exposure to as long as 13 days later. These findings continue to support the CDC recommendation of self-quarantine and monitoring of symptoms for 14 days post exposure.

COVID 19: Average incubation period for COVID-19 is 2 to14 days (but as little as 1 day), median time is 4-5 days. You have more chance of having an accurate test result if you have symptoms or you wait at least a few days after COVID 19 contact. COVID 19 can be transmitted by presymptomatic and asymptomatic individuals.