What Causes Delay In Periods?

I've been on the implanon for 9 years in may was the 9th year and I haven't gotten it removed I had maybe 5 periods within the 9 years but I've had a regular period every month since May except 2 months I didn't have one I took 2 test both negative had one on December now I'm late 5 days? Is it possible to come out pregnant? And how long after removal with I become fertile again