Mucus plug/cervix question

I went walking around for like idk, 10 minutes + a short bumpy boat ride. Then a few hours later I lose a piece of my mucus plus + some cramping, then find out the next day I have a short cervix at 33 weeks.

If I continue walking around a lot, could that increase my chances of my cervix dilating? Or is that not up to me & more so my baby? lol. (Not that I want to dilate early) I just plan on walking around a lot & swimming this weekend/week on my little vacation. Worried about my short cervix & this is my second pregnancy.