Pregnant on Mirena?

I got the mirena about 6 or 7 months ago after my now 8 month old was born. I breastfeed but she is down to nursing only 4 times a day. I have not gotten a period since I had her but I have had some spotting here and there. My husband and I don't have sex frequently (4 kids ages 4 and under, we are exhausted). I have been feeling super tired and randomly nauseous but it seems so unlikely to be pregnant. Does this look like an evap or faint line?