Pessaries - 3dp5dt

I had my FET on Monday July 5 (any transfer twins here?) and all was good in and under the hood with the pessaries until this morning.
I pushed the pessary in but it didn’t go up like it has been this whole time. It got blocked by my suddenly low and kind of hard cervix. The pessary slipped out and I had to re-angle it to get it back in there. Sorry if TMI. The same thing has just happened with my evening pessary and my cervix is still low, still hard.
I’ve heard ‘high and soft’ is the pregnancy gold standard.
Has anyone got any advice here? Should I be concerned? Anyone notice anything like this before a successful transfer?