Cervic measuring short?

I had my anatomy scan last week and they are now keeping an eye on my cervic. 2.5 is considered to be short for a cervic and I'm
Measuring 2.8. They said if it goes any shorter I'll be given some sort of vaginal treatment. Anyone else experience something like this? With my first pregnancy I  almost had my daughter at 35 weeks and was dialated at 5.5 cm already. Luckily they stopped it and was able to keep her in until 39 weeks.