Pregnant?

I've had my Mirena IUD in since April '17. I have two children aged 3 and 2. I think as a parent you have a gut feeling whenever you're pregnant as I did twice before (test showed pregnant before missed period).

I had a feeling the past week or so and I took a test Friday. It showed a Vvvvvv faint line, like almost barely noticeable but it is 9 days before a missed period (which are irregular anyway)

Has anybody had experience with falling pregnant on the coil?