Is it just my period coming back?😞

I've had my Mirena for 4 years. July was 4 years and since then, I've noticed spotting or light bleeding, mood swings and acne. I haven't had acne like this since high school. I haven't bled since the end of 2019. I've never been able to feel my strings but my husband says it's still there. My mood swings are all over the place but when I'm sad, I'm really really sad (crying, lots of crying). I know it's good for 8 years and I never really had heavy bleeding prior to the mirena. Should I be concerned about a high chance of getting pregnant? Or is it just the hormones slowly wearing off and I shouldn't worry about getting pregnant? My period is coming back isn't it😞