Hi A.,
I struggled with infertility for quite awhile, was blessed with a baby girl, then blessed with another, seven years later! My experience with birth control is limited mostly to the last four years, since the birth of my second daughter. I am 37.
The NuvaRing was, for me, FANTASTIC. I used it for four years and found it easy to use, relatively inexpensive, and without the issue of having to remember to take a pill daily. My periods came like clockwork. There is no need to visit the doctor other than for your yearly exam. I would highly recommend it to anyone who want reliable and easy-to-use birth control but wishes to retain the option of discontinuing use quickly and easily if they should decide to begin trying for another child. The hormones are low dose and localized and are out of your system rather quickly.
As it would not be good for my health to have another child, last fall I made the decision to try a more permanent option, one that would not require a run to the pharmacy every month. I was not completely comfortable with the idea of permanent sterilization, and so opted for the Mirena IUD. It cost about $1000, and one can buy quite a few Nuva rings for that price, but is working wonderfully for me. A short visit to the doctor's office, a day or two of slight spotting and discomfort, and that was it. My periods were a bit long and irregular at first, but have since regulated. One bonus... let's just say that things are a bit more enjoyable in the bedroom due to the difference in hormones. ;-)
My recommendation would be to try the NuvaRing until you are sure your family is complete, then switch to the Mirena, which is less hassle and more cost-effective in the long run. You would have to keep the Mirena in for at least two years, in order for it to be less expensive than the NuvaRing, over time. But that is just my experience and very humble opinion.
Good Luck!
A.