Is it normal to be irregular when you first get your period?

Totally normal. You might skip a month. Then have a longer or shorter period. Then you might go back to a normal period. You get the picture.

This process is important, though, because your body is learning to settle into a regular menstrual cycle. In a few months, your body should figure out which cycle is best for you. That might mean a period every 20 days, 28 days, 34 days, or something in between. Some girls have irregular periods their whole lives. But if the bleeding doesn’t become more regular, see a doctor, especially if you’re sexually active.