Possible pregnancy

So I’ve had the mirena since 2015. I just had my period at the beginning of the month. I had one bad day of bleeding and the rest I spotted. I have just started to feel horrible at night and in the morning. I took a pregnancy test at home last night and it was negative. I decided to take another test today in the morning and as I was going to take it I notice the one I took yesterday now is positive. The one I took this morning is still showing negative. Is it possible I could be pregnant ??