what counts as a period??

my endo told me “if you bleed it counts” but I’m questioning that right now. In September I started inositol and I’ve bled every month since which is literally incredible the fact that I’m somewhat regular is awesome. Except my period has been so light and so short (2 days, maybe 3) that now I’m wondering if it’s just spotting?? It’s never been this light or short before and I’m 27, I’ve had my period since I was 14, it’s not like I’m super young. Although it was super irregular when I wasn’t on birth control.