Can I be pregnant

Hi i and my husband had unprotected s*x on 12th day of my period on Oct 13 and now the period is late by 11days usually i get my periods in 28-30 days and cycle is of 4-5 days but now the period is late and for last 5 days i have sever vomits after anything i eat and continuous fever and cold i am worried about pregnancy please suggest what to do