mirena iud

I’ve had the mirena iud for about 9 months or so and i haven’t had a period since november and that lasted 2 and a half weeks.

Is it still normal to have cramps at 9 months after insertion? I had one that felt like a contraction in the middle of the night a couple days ago. Besides that it just feels like an uncomfortable feeling like a cramp. I checked the string and i think it’s there. My doctor also checked it a couple months ago and said it was fine.