Let me ask you this: Has the amount decreased gradually over a period of time, or is the low volume always been a concern? The reason I ask is that I have noticed a gradual decrease in my amount over the last 10 years, and I am in my early 40s. My amounts were pretty good size from my teens thru about age 30. Could be just the aging process. Good luck and I hope this helps!
So, why is a 14 year-old female virgin interested in a question such as this one?? :)
Testosterone can be a possible cause - but you would likely be experiencing other symptoms of low testosterone (decreased energy, depressed mood, erectile problems, etc). You can always talk to your doctor about this and have him/her check your testosterone to make sure it is within normal range.
Can that have anything to do with testosterone levels?
There is a lot of variability in terms of how much semen is expelled during ejaculation. If you masturbate or have sex frequently, this may result in less semen. Also, not drinking enough fluids may do the same.