Starting period 2-4 days after last pill. Normal?

For a majority of my pill taking lifetime (about two years) my period would start 1-2 days after my last hormone pill (meaning I've been taking placebo for two days then it begins). A little more recently it's been starting after 3-4 days into the placebo. Is this normal?
Previously I didn't really care - the whole reason I started was just to feel normal and have a monthly period. Now I'm sexually active in a relationship and while I still really only care about having my period (and not being pregnant), I'm wondering if I should be concerned especially since it went from two days to starting after four.