I used the diaphragm for years and years when I was younger. No problems but kinda messy.
Now I have an IUD. We are talking HEAVEN. The new generation ones are very safe. Nothing like the reports of perforation and death like in the 60's and 70's. One IUD lasts 10 years. No hormones, no remembering anything ever. The only caveat is that you should only use them in a long term commited relationship, because if you get sexually transmitted diseases, esp gonorrhea, the IUD will make things worse.
The day it was inserted I was crampy and sick feeling and sweaty and uncomfortable. That was it. Not a single symptom since. That was 6 years ago.
Some people experience heavier than normal periods with an IUD. Not great for someone who already has heavy crampy periods. I don't have that side effect.
Next stop - hubby to get snipped!