Has anyone developed irregular periods?

Monica • Boy mom 👦🏻 TTC baby #2
Has anyone had regular periods throughout their life and then sudenly started having irregular periods?
I ask because I've had regular periods for the past 10 years or so of my life and then last month my period was late and of course I freaked out cause I thought I could be pregnant, thank God I wasn't, but I'm officially late again this month and of course I'm freaking out again. I already took a test which came out negative, but could there be some underlying problem I should be worried about?