How To Treat Severe Cramps In Leg After Taking Nuvaring?

I have been taking nuvaring for 2 months now..The last little bit I have been getting cramps in the calfs of my legs frequently. The week it was out I had no cramps.Also I am fairly dark skined, I went to the tanning bed and ended up getting actually blistered. I usually NEVER burn, may get a little red but nothing like that. Nuvaring is the only thing I have done different! Could this be due to nuvaring? Should I continue use?