Hi Snoopy,
I didn't want to just read and run. Unless your coil was producing hormones (but I don't know of any which do this), you should still ovulate when using it, it's just that any embie can't 'stick' to your uterus. Have you tried getting your day 1-3 bloods and day 21 bloods done at your GP? If it transpires that you aren't ovulating, there are drugs that can help with this, but I'd suggest you get an appt with a fertility clinic to discuss.
Jo
x