Failiure? Periods

I haven't had my period since the implant, does that mean I'm likely to be pregnant? Or it's failed? Or worked? If it failed surely that means I'll still have my periods just like normal because it's done nothing... But how do I know if the implant has worked or not due to my periods?

[Goodhandn]

It is normal to have no periods with the implant, about a third of people will have no periods for 3 years. The implant is very effective so it is highly unlikely for you to get pregnant.