It depends on the politics of your work place. They should push it through and in an ideal world your grievance would be upheld by hr management would accept it and it would offer you some protection if they complain you have had time off. as you are pregnant they cant really touch you though.
However if you know by making that complaint your workplace managers are going to make life difficult it isnt worth it for 2 weeks off before your mat leave starts . Particularly as they really are the cause, sod anyone who thinks you are lazy.
Sorry 4 long post if I ramble on! Just wondering what others would do in my situation. I'm currently 27 weeks pregnant, I work 12 hour night shifts, which have become very difficult for a number of reasons (left on own, bending, lifting patients, length of shift, nights) also I have not been particularly well this pregnancy, suffering nausea, bp problems n headaches mainly for which I have had to take odd shift off sick. I have requested a risk assessment so I can adjust my hours n amend duties under advise of gp n union, this has never been done despite hr, occy health n union insisting it was urgent I've gone to gp this morning for fit note to help push the issue n she has insisted I dont return to work and signed me off sick until maternity leave starts at 29 weeks. Do I still raise this all as a grievance? I feel because of there lack of assessment I have been forced to be off sick n look like a lazy person, also my maternity has not yet been conformed date it will start so how will this happen if I'm now off sick?!! Any help would be appreciated!