Hi, and thank you for coming to JustAnswer.com with your question.
You are young, but that should work in your favor, not against you, in terms of getting pregnant.
Have you ever had a sexually transmitted disease?
After three years of trying it seems appropriate to speak to your ob/gyn about starting to do some testing.
If you've had an STD then there is a possibility of scarring that would make it difficult to get pregnant.
Most likely the first step should be for you doctor to test your hormone levels and make sure they are within normal range, and going up and down as expected based on the time of month.
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