You will be assimilated, resistance is futile 4

Every afternoon since last Wednesday I have been taking MiniMad to Preschool.  every afternoon without fail I have received a phone call asking me to come and collect him early.
It happened again today.  He is fine when I drop him off, he runs and pops his name on the board and gets stuck in to something, coming back to give me a quick kiss, but then about half way through his session the tears come from nowhere.
He can seemingly be fine, he was coming down the slide this afternoon, when all of sudden he bursts in to floods or tears and becomes inconsolable.
I took in his dummy and comforter in case this happened and the staff have tried giving him them to calm him down, which has worked, but then he will get back on with things and all of a sudden burst into tears again.
The staff are fantastic and ring me  and I immediately go and get him and he runs into my arms and all is forgiven.  A big smile come on to his face and he insists that we go for a cuddle and all is well with the world.
As a mum this is so hard, especially as he has always been my confident, cheery and content second child, well he was until I went in to hospital earlier in the year.  We had prepared both the boys as best we could for the operation, but you can only cover so many bases and with all the complications I suffered and the readmitting he went to pieces.  We have been working hard to resolve these issues.  I always do what I say I will to reinforce my always coming back for him.  Yesterday I sat outside the school in the car, so unsure if I was doing the right thing for him, me and our family making him go to Preschool.
The hard thing is I am going back into hospital at the beginning of November and thought that Preschool would give him some semblance of routine and normality in what will be a sea full of uncertainty.  SO I have decided that I am going to be a Borg Queen and resistance is futile, he will be assimilated.  I am going to preserve and we will review the situation next week.
Sometimes being a mummy is like I am in charge of the Starship Enterprise!!