What Causes Itching On Using Tampons?

I've been using tampons for about 6 years now with apsolutly no problem ,and about 6 months ago every time i use them i get Unbelievably itchy,I used to think i was just one of those unlucky ladys pron to yeast infections (only symptom i have is itching)but i think something else is up...anyone else have this problem?