Irregular period...?

Hey ladies, so I have a period question😅 When I was younger (middle school through early high school), I had very irregular periods. Meaning sometimes I would skip a month or two. I knew this was normal for someone my age at the time. But now I have a new problem. Earlier this year, I started BC control and it made my period work like clock work! I am 19 now and this week there was one day where I missed the pill (traveling threw me off a bit) and I started my period for the 2nd time in a month. My last period came right on time as expected. This was the week before last week. I started a 2nd period today. Is this supposed to happen every now and then? Is this due to missing a pill?

Edit: I’m not experiencing any pain, nausea/vomiting, or any other “out of the ordinary” symptoms other than I’m moody as usual when I’m on my period.