You should be concerned as it is not regular you will have to take extra care.
Doubleplusgood if it's a boy.
talk with a parent
Yes, you should be concerned, and you need to have a vet look at it as soon as possible. It is impossible to say what it is without proper medical advice.
There could be many different reasons for irregular periods. You should see a gynecologist if you are concerned.
My 36 year old very fit daughter has very low blood pressure, 96/63. Is this something she should be concerned about.
That should be ok, but a 6 year old should not be in there for an extended period.
I would be. Take him to his pediatrician.
Most girls get their first period when their 12.5, so no.
If you have not had your period in over a year then this is most likely a medical problem and should go see a doctor AS SOON AS POSSIBLE!
kidney count was 42 one year ago it was 43 should i be concerned
Don't expect a regular 28 day cycle for at least a year after that you should be on schedule
It could be 80+. There is nothing to be concerned about unless you are over 120.