Sore breasts for over a week, Mirena, negative tests

I’ve had my Mirena for almost 5 years. Recently I have had very sore breasts lasting over a week. This happens occasionally from my Mirena but it will only last 2 days. This is the longest this soreness has occurred. I do not get my period. I have taken several pregnancy tests over the past week and they’ve all come back negative. I took 1 digital test and a couple of strip tests that came back negative. Has anyone else experienced this kind of thing with mirena use? In the first 3 years I never had any symptoms. I have an apt with my OBGYN mid April. Let me know what you think!