You cannot claim to have irregular periods if they happen in the range of plus minus one week of your actual date. That range is usually acceptable. Only if you miss an entire month, or menstruate more than once per month is it advisable to get assessed otherwise day to day factors have mild effects on ovulation and consequently menstruation.
Next Steps
The best way is to track your cycle over a period of year to see a net average duration of your cycle. If most of your cycles fluctuate more than 35 days to less than 21 days then I would recommend a gyne consultation.