ULTRASOUND TECH OR EXPERIENCE WITH CERVIX ISSUES ADVICE NEEDED:

I'm high risk due to my son coming at 27 weeks. (He's a healthy 2 year old now) so I was getting my cervix checked once a month and yesterday was my last one. My Dr didnt seem concerned and said it would be my last cervical ultrasound bc everything looked good. She said my cervical length was 3cm, which is good bc it needed to be above 2.5. BUT I've been having sharp pains in that area that just about double me over or sharp pain when I bend over.

This was my 19 week check. To me it looks completely closed and Dr said it was long enough. I think it was 3.5cm.

This is my 23 week check. It was 3cm BUT I noticed it looks like it's opening some on the inside near the baby.

Am I just being paranoid and looking too much into it or did my Dr just not think it was concerning bc it's long enough..