Hi Helsurf - I didn't get antibiotics before or after the elective stitch, but I did have them before, during and after for the emergency stitch - my cervix was open so it was essential to keep any potential bugs at bay. Some consultants give them routinely, others don't
Kate hun - I so feel for you

It is mentally draining being in a state of high anxiety trhoughout a cerclage pregnancy - I remember it well and don't envy you the next few weeks purely for that reason. Even tho my dh loves me dearly and found the whole thing stressful too, he still couldn't understand my constant sense of dread, fear and moving back and forth between worries. I cried nightly to him from 21 to 28wks convinced I wasn't gonna make it, and feeling devastated at the thought of another NICU battle - this time with two babies!
I felt constantly that the boys were going to just fall out, that the stitch might be infected, that I would go into labour any minute due the ever-present painless, yet very real contractions

It is nothing short of hellish, and you don't have to explain the feeling, or justify it here even for one second - we all understand and are totally with you
As for infection, it is unlikely hun and very, very rare if the cervix is closed (even if short and closed). It does happen, but not often. There is nothing you can do as such except to get screened regularly, and/or get yourself to labour suite if you feel anything unusual or like preterm labour. I have to say tho that I could have easily gone into hospital every day with signs of early labour because I was never free of labour-like symptoms. Needless to say I still made it relatively easily to 38wks, and none of those feelings amounted to anything
It was interesting to note in the NICE guidelines that one of the IC studies showed that ladies with a stitch present to hospital more than those without, and many of them need meds to ease contractions. I was never put on a monitor, but I feel sure if I had been it would have shown uterine contractions - not enough to cause cervical changes, but enough to terrify me. I am sure that these side effects are stitch-related (and probably made worse by the fact I was carrying two), and tho usually harmless they are an added anxiety for IC women. You can't have a huge piece of typewriter-like tape sewn through your cervix without your body having something to say about it, it is a foreign body afterall!
All I can say hun is that you are doing everything that can be done to get this baby to term. Infection and preterm labour are possible with IC, but rare. Blood in your urine is essentially nothing to worry about and the bleeding indicative of preterm labour/infection is significant and unmistakable. There is really no doubting when you have moved from having a structurally weak cervix, to being in preterm labour hun. How long is it since your surgery now? Are you getting swabs done around 20wks? It is now a part of prem prevention in many hospitals.
As for flu jab, I had it at 15wks with the twins, and didn't have any issues with it. Risk of flu complications are more common in pregnant women so I didn't hesitate to get it. If it helps, my preemie daughter has had it every yr since she was born, and the rest of the family get it too - none of us has had any ill effects from it

x