I was going to post something like this, Girls periods in their first year are not that regular I wouldn't panic yet. My daughter was 14 when she got her period and was pretty normal and regular and the second year not to bad but started to get unregular and in the past 4 months her period went nuts, she is now 17 and she was having a period every two weeks and just last month started it and it went for almost a whole month, I took her back to the gynocologist and she finally put her on a birth control pill and three days later her period finally stopped, as for regulating, she has yet to start to see if all is well. she is just happy to have it stop,
I have one more daughter to go through this, right now she is 12 and hasn't started her period yet.