when did get your period the first month on nuvaring?

Ella
I took the nuvaring out on Monday the 13th and today the 17th I still haven't gotten my period, I took a pregnancy test and it was negative so I'm not worried I'm pregnant. However I had the IUD for 3 years so this will be my first period in 3 years. I'm worried it won't come? At what point should I call my doctor