Anyone have the McKenna before?

I had a strong history or preterm birth, I had never actually carried full term until now. This time around my dr prescribed the McKenna, I’d say it worked. My last shot was at 36 weeks and I am now 38+3. It makes me nervous to be honest to still be pregnant, I have been getting increased anxiety over the last week wondering when will baby arrives. Is something wrong. Why hasn’t baby come yet. I understand that baby is still maturing which I am so thankful for, after never carrying full term this should feel like a blessing to still be pregnant at this tome. I just can’t helped the questions that keep repeating over and over in my head. Has anyone ever used the McKenna and then had issues going over due?