Nexplanon question

I have had nexplanon for a year and eight months. I absolutely love it!! I had it inserted in April of 2013 and had a period in May like regular but since then have not experienced and bleeding. I would get sysmptoms; headache, backache, bloating, etc, but never bleeding. This passed week I have had a full length period out of no where. Has anyone else experienced this? Is it normal or should I call my doctor?