First of all do not blame anybody for STDs or VDs at all. You could only blame yourself. It is a wild card.
Your age has nothing to do with this at all. You should go and see a Gynecologist and ask her/him in private about those things.
Usually they have HIV/AIDS testing facilities but again you have to ask yourself what kind of person you was with and where this was with and if there was something off?
Beyond that you have to chose partners wisely. Many people who get around could easily have STDs so do not think if the person is good looking or by your definition "handsome" they are excluded. That is why we stay within a close proximity of the people we associate with.