is this normal?

These past few months my periods have been late for a day or two, and on the first day it will be very light, not enough for a pad. This is new for me as I have always been, not heavy, but not light either on the first day. Then the rest of the days my period will be like I was used to. Is this normal? Or should I be worried? Maybe my cycle is changing? I'm not worried but I thought I'd ask if anyone has gone through something similar. I'm 19 and I've had periods since I was 12 if that helps.