Mirena, but feel pregnant😞

So I've been on mirena for almost a complete year now, no problems other than I'm extremely moody some days, weight gain, acne, and rarely ever get a period anymore (but I'm not complaining!) My bf and I never use condoms or any protection besides mirena. But the past couple weeks I've felt really bloated, couple headaches here and there, falling asleep as soon as I sit down, I always eat like a crazy person so I guess that's nothing out of the ordinary, but I've had very mild cramping the past two days now and when I wipe it's a light light brown-pink. I just don't want to get in the mindset that it's a pregnancy because I have mirena! But as the days go by the more I question what's really going on?! What do you guys think??