Period lasted for less than 24 hours.

It usually lasts between 2-3 days. 4 at the longest. Last time I had any period last less than 24 hours was before I was sexually active w my husband. At that time, it was like a 12 hour period and done. This month, I have like no cramps and it's pretty much done now and not only has it been less than 24 hours, it was lighter than usual. (I'm usually light-medium flow)

Is this normal? Should I be worried that this could be implantation bleeding, or no?