Cervix length??

MamaGoose
I am 30 weeks 4 days with my 4th. I went in for a check up this morning and they are a little corner bc cervix measuring 2.9 cm. -- apparently a significant change from my last appt 4 weeks ago at 4.6 cm.
I am having contractions, as I have with all my pregnancies... But last night they were in a pattern every 5 minutes and strong. 
Should I be concerened?
Anyone go through this? 

Glow Resources

Let’s Glow

Glow is here for you on your path to pregnancy

Glow helps you navigate your fertility journey with smart tools, personalized insights, and guidance from medical experts who understand what matters most.

25+ million

Users

4.8 stars

200k+ app ratings

20+

Medical advisors