Is it okay to worry about being sick??

Around two years ago , I got a really bad flu and or cold on my birthday (December 13th for reference) and every year since , I just stress around this time of year , especially with everyone HAVING a cold already (including me) I've just recovered from a rather nasty cold but I'm worried about getting the flu , especially so close to my birthday Is this a genuine concern or am I being abit too paranoid??