I have had the Implnon for only a few months now. and i started my peroid ten days ago and it's still going?!?! I need some answers! I understand that this birh control can change my menstral cycle...but isn't ten days a little too long?? Normaly my periords only last maybe four days. I have no pain from my period, just a constant head ace thats been going on and off for three days now!?!?! A few weeks ago i was haveing some pain were my implnon is located, but i just ignored it. Does anyone have an explnation of why my period has been going on for ten days straight? Is it going to just keep going?