It sounds like you're not ovulating on your own. Ovulation is what eventually triggers your period. If you don't ovulate, you usually don't get your period either.
There are several reasons you might not be ovulating. Stress can be one of them and I would suggest doing everything you can to reduce the amount of stress you have regardless of trying to conceive or not. Stress can effect your future pregnancy(ies) as well. Another thing I know that can effect your ovulation is your weight. If you over or under weight your hormones don't work as well as they do if you're a healthy weight. Your body needs at least some fat to process estrogen, but too much fat slows it down too. There are also some thyroid conditions that effect ovulation. Your doctor can check you for those.
If all of the above has been ruled out there are drugs and treatments out there to induce ovulation (like Clomid). Since you are under 35 your doctor will most likely want you to try on your own for a year to get pregnant. But since your periods are so irregular, your doctor may intervene sooner. The good thing with starting so young is that you have time on your side. From what I've read less than 1% of women under the age of 25 have trouble conceiving after two years of trying. It’s the 1% that then needs medical intervention.
I would say your first step should be to make a doctor's appointment with an OBGYN. Explain that your periods are irregular and you want to regulate them in order to become pregnant. The doctor should take it from there - regardless of your age. :) Good luck!!
P.S. My parents were 19 when they got married and 22 when they had me. They've been married for 38 years now. <3
Thank you for all of your advice you really helped!