No you shouldn't be worried.How many times has the world been predicted to end ? Loads so what makes you think this one is right.Because of a calendar ? The calendar and the calendars right the world should have already ended as the calendar doesn't have leap years and if we didnt have leap years it would be in 2013 right now
No, don't worry. Just spend all your money on radioactivity suits and gear and buy huge life insurance policies on all your family members, sell all your stuff cuz you will lose it anyway. Do all this and you will be just fine