Been ttc for almost 2 years

Marielis
Ive been been trying to conceive since july 2015 & nothing. The last 4 months my period has been 5+ days late. I was suppose to get this period May 19 & still nothing as well. Every time I take a test though its a big fat negative. My doctor said I would have to wait a year of ttc to be able to get tested for fertility problems now that I asked her again to be tested she said, "you're too young to be ttc & I dont think they test on people your age, you have plenty of reproductive years left" Is this true ? I am 20 years old (21 in october if that makes any difference)