cervix opening

I'm currently 22 weeks with fraternal twins. At my appointment today I was told my cervix is starting to open but not to worry too much about it. I have another appointment in two weeks to check if it's opening more or staying the same. Just wanted to see if anyone else had this happen and still had no issue keeping the babies in full term (for twins). Even though they said not to worry, that's all I can think about now. I really didn't want to end up on bed rest 😭