I’ve had a copper coil since around mid April. My periods have become heavier and more painful but always on time and I track them with an app called Ovia. I’m a week late, getting super tired, having back pains and feeling nauseous. With my first, that’s how I was feeling in the early weeks of pregnancy so naturally I’m thinking that’s what it is. But I was told the copper coil is over 99% effective, which is leaving me quite confused.