Will this be the first time you've taken the pills? Or did you stop and start them again?

If you were on them before, and then stopped, that could cause your period to be weird. And it might take a couples months of the pill for your period to regulate, anyway.

If you period was just late, that could be from lots of things. Stress, eating patterns, just being young.... whatever.

Either way, go ahead and start taking the pills. It won't hurt anything. It will only help to regulate your period. But don't be surprised if your period still isn't regular right away, like I said, it might take a few months to adjust to the pills.