Copper coil late period? Anyone else had this?

[Milkmachinemadness]

I've posted on family planning but need somewhere with more traffic . I've had copper coil since November and had 2 periods since, I'm still bfeeding 10 month old. My period is now a few days late I'm terrified it could be a pregnancy as I've read so many stories of this failing. Wish I'd never had this now I shudda stuck to my horrible hormone filled pill:( I can't buy a test today but will get one tommorow . Looking for some reassurance for now :(