Do I have a problem??? Penis size?

Well I'm 14 years old,and i have quite an amout of pubic hair,some armpit hair,and no facial hair,but my Penis is only 3 inches long (when hard) I'm worried I won't grow because my gf already wants oral but I don't want her to see I'm only 3 inches long(embarrassing and disappointing) please,is this normal? Should I see a doctor?