I think the coil can be very different from woman to woman, some people have nothing but great things to say about it, just didnt work out for me! Am very disapointed as was hoping it would be answer to my problems!
I believe the Marina coil once its settled should make periods lighter and in some cases stop them all together but the initial spotting can be for up to 6 months.
The diaphagm works by covering the cervix to prevent sperm passing it you also use with spermicide with it I found it very difficult at first and gave up but found I was over complicating things and its really quite simple, they arnt really recommended for women my age more for older women who are not quite as fertile as they are not as effective as other methods of contraception best thing to do is discuss your options with a doctor or at a brook clinic, I had to go to a brook clinic for diaphragm fitting as doctor couldnt do it!