To some degree, a slight metallic smell is not too unusual when having your period. Your blood is made up of iron, hence the metallic smell. If you have noticed other changes or the smell seems to be strong, make an appointment to talk to your healthcare provider about the change that you notice.
A metallic smell is quite common; you may have had it before and just never noticed. Most blood does have a metallic smell. Though be sure to read health expert Sandy’s answer, she can probably explain why. In fact, I plan to read Sandy’s answer because now I’m curious.
The metallic smell is normal. It’s just iron in your blood. I wouldn’t worry too much. If you feel it’s become too overwhelming, talk to your healthcare professional. It’s always good to talk to them when any sudden changes happen or you’re not sure about something.