Is it normal period problems ;(

if your pretty young its normal to have irregular periods but if it goes on til late adolescence and adulthood you might have PCOS like me.. better go to an ob gyn and get checked.

If you’ve been under stress, changed your diet for better or worse, or have low body fat, it can disrupt your normal cycle. Although you mention you’ve skipped a month before, you may not have a typical monthly cycle. Talk it over with an older female in your family, to see if they’ve experienced the same thing, and if it continues you should see a GYN who can help you regulate your cycles and make sure everything is okay.

It could depend on your age, which you don't mention. It's fairly common for adolescent girls to have irregular periods, but if you're worried about it see your doctor.

If you've lost a lot of weight that can cause it.

see a gynecologist, you might have to go on pills to kickstart the period

It depends on how long ago you got your period?

I think you should see a doctor.
If you usually don't go 4 months without a period then there may be something wrong.