Nuvaring side effects

So I've switched from the copper IUD to the nuvaring this month and I'm feeling all sorts of things, which I know can happen. I basically can't stand nor want hormones but I just got no choice atm since the copper iud didn't work so well for me. So I started with the nuvaring on my 5th cycle day and I was feeling pretty good the first days but then after a couple days I was starting to feel tired, nauseous, had major mood swings and I had "spotting" (nearly a period) for about 2/3 weeks... But one day at work it kind of felt like i ovulated anyways, so I really don't know what to think of that and a couple days after that my breast were starting to hurt quite a lot on the sides and under.  So what I'm wondering about is, could this be another side effect or is it something else and how have you experienced the nuvaring in the beginning? Did you still get different side effects even though you were on the nuvaring for a couple of weeks? 
And maybe good to know, my boyfriend and i are super fertile together, so that's why I kind of wonder if it's actually working or that it just might has failed😅
Thanks in advance🙋🏻