I been using NuvaRing for the first time from July 25 and I took ...

I been using NuvaRing for the first time from July 25 and I took it out on the 28 of July.Why? Because I had big blood clots. These clots really scared me. I am not use to anything like that. My periods are very light and normal, so when I seen this I said no way. I have low blood anyway and I felt very very light headed. I also felt tightness in my legs. I could not sleep at all. I wake up in the middle of night. I believe the FDA need to do more study on this birth control. Doctors don't really know much about this NuvaRing.