I have kids and have been single for nearly 3 years, and my periods started to be irregular

Hi my name is Amanda I a have?   I had a kids like e years ago and I been ssingle for  3 years and haven't done anything with a any one.  But when I get my period  it late some time 3 or 4 days some times more  but when I'm done like 5 or 6 months later I start my period. Ago I was wondering what's wrong with my and y I'm getting every 5 till 6 months later