Could i be pregnant? PLEASE HELP?

the first day of my last period was the 20th november, i had unprotected with my husband on the 27th and around about then aswel. i wasnt sure on when i would ovulate as my period has been abit irregular. it is now the 8th december i have been feeling very tired (even tho i havent done much other then wrap xmas prezzies) very sore (not ,s) been felling abit sickly but havent been sick and can get sore heads from time to time. Could i be pregnant? Someone please help.