If you're not sexually active, there isnt a big urgent need to get on birth control - unless a doctor has recommended it for you.
I really regret having started taking birth control when I was so young as a teenager, because I swear I think it threw off my natural system and cycle to be on all those hormones.
If it were me, I would say stay off the birth control unless you absolutely need it!
Missed periods and irregular periods can be normal in teenagers. But if you’re a teen and you haven’t had your period for at least three months you should consult a physician. Sometimes, birth control pills are given to help regulate your period. They can also cause you to experience a missed period.
Any kind of birth control can regulate your period so long as it has hormones. Just talk to your gynecologist or general physician about it at your next appointment! Also mention that your periods did become irregular after having been regular for quite some time in case the doctor wants to do any tests.