My ovulation was 27th november. 7 days later till this moment i have been down with headache, cold, vomiting, high temperature. what could be the cause?

Hard to guess: Fever, chills, aches, cold symptoms together are called a flu-like illness. Many causes exist, mostly infectious, sometimes not. With mild symptoms, we call it a cold or upper respiratory infection. With moderate or severe symptoms, we call it the flu. Sometimes a flu-like illness lasts a few days, other times 2 weeks. If symptoms started in the last 2 days, a doctor may use Tamiflu if influenza.