Getting married at a young age doesn't lead to poverty. Getting pregnant and having to raise a kid at a young age leads you to poverty especially if you have too many of them or the parents themselves doesn't have the financial capacity to raise a kid properly. I know of people who got married early and are still making profit.
Yeah! What is most important is for you both to understand yourself, be matured enough to reason and then you will be fine. I have seen people who married at the age of 18 - 20 doing better than those that married even at 30 and above. Most times, what usually cause some issues is when the problem of unwanted pregnance comes in and you get forced somehow into marriage of some sort, but in a way you both made the decision to do what you wanted to do, I do not see anything at all to cause economic problem.