I recommend the IUD! Don't feel a thing and don't have to worry about it for 3-5 years
I have the nexplanon implant and it works for me. Really effective and it lasts you for 3 years.
I have used the Nuvaring off and on for years. I love it. You put it in and leave it in for 21 days and then remove it for 7 days to have a period. Then simply put a new one in. No worries about taking a pill at the same time everyday and I also found that I have no side effects from it as I have bad side effects from all the other pill forms if birtcontol. For me it has been the best. Everyone is different though.
DO NOT DO THE IUD. I had the IUD for 6 months and then suddenly started getting bad cramps that were so painful nothing helped the pain. They lasted for two weeks and then I finally caved and made a doctor appointment. When I tried to get it removed they couldn't find it with the ultrasound, but did eventually. When they did they found out that it had caused an infection and when they were trying to remove it they had difficulty. They had to burn the lining of my vagina to get to it and now I'm result I will not be able to have children. I do not recommend this form of birth control to anyone! Not to mention how painful it was inserting. I nearly passed out.
I've had the mirena IUD since 2011 and haven't had any problems. Except a couple of them fell out due to other reasons but I have always had them replaced. It has been the best thing for me because it's the only thing I've tried that helped with my heavy periods. Now I can travel even when I'm on my period because my periods are so light that I only need the thinnest pads. It's been great for me.