Diva cup help question....tmi

Ashley
I bought a Diva cup, and I love it. But I don't know how to tell if my period is heavy or light or medium. I've always had to use pads because tampons give me migraines. I normally have a light day, two heavy, and then spotting for 2-3days. I had to wear pads for the first two days because my cup came in late. Well my first two days were heavy. I've been wearing the cup all day today and I emptied it twice and it hasn't even reached the 1/4 mark. How do I tell how heavy or light I am? Any ideas would be helpful.