Welcome to the forum!
A lot of folks do it accidentally, so it's not uncommon, but you might be adjusting your front sight post in the wrong direction. To get the point of bullet impact to go down on the target, you need to raise the front sight up; to get the point of bullet impact on the target to go up, you need to make the top of the front sight post lower. It's the opposite if you're adjusting the rear sight!
So I think if we were both at the range and talking, I would suggest raising (unscrewing) your front sight post several turns, and see if you start hitting closer to where you're aiming - and then adjust as needed!
And finally, if your rear sight has range markings like many AR sights, double check and make sure its on the shortest/lowest setting, and not accidentally adjusted for shooting at 600 or 800 yards. There's a lot of good info on different approaches to zeroing an AR available online; here's one example for use with an A2-type rear sight:
The ibz is a great way to sight in your AR15, you just need an allen key and some knowledge.
thenewrifleman.com