Period changes while on depo?

So i've been on the depo shot for about a year now. As far as I can remember, i've bled continuously for months at the time to the point where I always needed to wear panty liners and pads. I was always on time to get my shot. Since my last shot in late february, i haven't bled much at all. It's weird honestly, I was so used to having a period everyday and it put my mind at ease knowing I couldn't be pregnant if i was bleeding that much.