Could Enlarged Breasts And Headaches Be Due To Fitting Of Coil?

Hi, I had the coil fitted 5 weeks ago, not had one bit of bleeding since, then the last 6 days Ive had tender breasts, nipples hurt to the touch, and they are enlarged, they are also darker around the edges,

I dont normally have this, specially not for 6 days, and increase in size. Would this be an affect of the coil? Or could I be pregnant? Im suffereing headaches also... not sure what to make of it, is this normal?