Spotting? Pregnant or period?

How did y’all tell the difference between spotting from your period starting and spotting from implantation bleeding? I was supposed to start my period today or tomorrow but normally when I get my period it’s VERY heavy and painful right away but today I had cramps in my back and side but not horrible or like my normal period cramps and when I went to the bathroom I saw I was spotting. Any tips on how to tell other than its not my normal? Me and my husband have been trying for almost 3 years to have a baby and I’ve been through 2 miscarriages in those 3 years so I don’t want to get my hopes up, but I don’t know how to tell...