Coil failed, AIBU to keep it in anyway?!

[Tealtights]

So I fell pregnant on the copper coil and miscarried this month, they scanned me and the coil is where it should be but the threads are gone. There's 5 years left in it, so I guess it was just that rare 1%. The consultant was urging me to go on something else, but I can't tolerate any kind of hormonal contraception (depression) and don't want to risk the Mirena. I'm not ready for my husband to have the snip (though he would). Would it be so unreasonable to just keep this one if it served me 5 years well? It's in place so there's no reason to think it'll happen again, it's going to happen to 1 in 100 women and what are the chances of it being me again? Or am I more susceptible for some reason? 5 years was a long time to be ok. Removal is going to be painful with the threads gone so I'd rather delay it!

I would want a new one, does the effectiveness wear off? Perhaps you're now at more than a 1% risk of it failing again.

I would think that as it's failed once, a new one would be the best option.

I also can't have most hormonal contraceptives, but I had the mirena, and I didn't have any terrible side effects and I never got pregnant.
Also, just to put your mind at ease about the removal, the GP who fitted it cut the threads clean off for reasons I don't understand but I digress. It was also slightly out of place and I was terrified of having it removed. I got referred to hospital to have a hysteroscopy to locate and remove it but the gynae managed to see it during an internal exam and just tugged it while I coughed really hard. Painless.

I would 100% have it out if the threads are not where they should be and it’s already failed to prevent pregnancy as you risk it migrating and perforating your uterus in the next five years.