Spotting is usually the size (on your underwear) of a loonie or toonie and doesn't bleed through your pants (it might bleed through your underwear though so wear a liner) and a period is much more blood and is a red color while spotting is more of a brown-red color or sometimes just brown. Also a loonie and toonie are Canadian coins (sorry I'm Canadian) and are just bigger than a quarter (American coin)

Don't be concerned about spotting. It's very normal. It's like a mini period and you usually only need a panty liner to protect your panties.