I am having a bit of a saga with my coil. Slowly my periods returned and a scan revealed it was a) too low and also out of date so was replaced in oct last year. Since them i have had regular full periods 
It was a NIGHTMARE to insert and i vowed never again. The dr was concerned about posirion so was rescanned and it was too low but dr told me it was ok - despite on both occasions ultrasonographer cautioning not to rely on.
I have had reason to be rescanned and whilst uterus looks healthy (no polyps or thickening) the fucking thing is even lower. It was 32mm from top of uterus and the limit is 24mm (apparently) it was 37mm this time (transvaginal probe this time) so maybe always so. US said almost at entrance to cervix
and not to rely for contraceptive. My dr previously stated was fine as mirena coils release hormones so will still work.
Really though??? Im having regular periods with full symptoms and i do not want to get pregnant. I am 48 so likely perimenopausal.
Cant get to see dr this week so am going to abstain from dtd. But fuck sake - i wish i never had the fucker. First two were fine. This one has been shit