Aging placenta😩 need some insight!!!!

Em

I had an elective ultrasound, but because I wasn’t technically a patient at the place the images can’t get sent to my doctor(my SOs mom works here so they give me ultrasounds occasionally) she said my placenta looks more aged than my pregnancy, I’m almost 24 weeks and my placenta looked in the 30s. Looking for mommas who have dealt with this. I haven’t smoked a cigarette since before I found out I was pregnant and I’m only taking medication classified as safe for pregnancy so why is this happening? I’m seeing my doctor tomorrow hoping they’ll have me go for another scan to see the actual age of my placenta but I’m stressing 😩 I don’t want my baby to come too early