Just Wondering....I Just Turned 47...I've Had A Mirena In For

just wondering....I just turned 47...I've had a mirena in for 3 years...I haven't had a period since... in January I had a period that lasted for a normal duration....had a pap in april then two days later had another period...pap test came back with endometrial cells. Just wondering about the chances are that the mirena needs to be changed...has happened before about 5 years ago with a biopsy that was negative...or should i be really worried
kin