How do I know if it is my period or PP bleeding?

Just got some blood yesterday after pushing my stroller around for some hours running errands. Don't know if it is my period or another phase of bleeding due to over walking.

Last time I carried baby in a wrap in town, got a brownish strong flow (about a week ago). But this time it is blood! Haven't had bright red blood in like 2 weeks.

Now am confused what it is. Because when I got home, it stopped. My period used not to stop until I was done.

Or is it me period still trying to find its normal after pregnancy?