Nexplanon and periods 2x month

I usually don't post to these forums but I got the nexplanon implant in late October of 2015. After 2 weeks, I spotted for about 10 weeks straight! Then stopped for over a month... Now this month ,I just got my second regular period with cramping and all (only a week apart!!). I'm getting married in two weeks and am panicing because I really don't want to be on my period. Anyone have experience to share? Does the irregularity ever resolve itself? Thanks