Pregnancy Risk Assessment not being followed

[Swift1602]

This is going to be more of a rant than anything. I’m currently 28 weeks pregnant and work in a special needs school.
I have placenta previa and have experienced some bleeding (not a huge amount though).
I have a risk assessment in place that states that I shouldn’t be doing any manual handling or physically supporting any students. I have a young man in my class who has been struggling a lot recently and when in crisis has been hitting, kicking, pulling hair and biting (for further context this young man is the same height as me and 14stone) - I have received no support for this and have ended up having to support him to keep himself and others safe.
Today I have been hit and bitten during an event in which both the deputy head and assistant head (who completed my risk assessment) were in the room. Took ten full minutes for them to offer any help. Just feeling fed up and feeling like getting signed off for the last two weeks of school!

Id get it in writing to them about what happened today and ask how 'we' can ensure that the risk assessment is followed in future as you are worroed about your pregnancy. This will probably put the fear into them and hopefully give them the impetus they need to take it seriously! If they dont then respond appropriately then you could get signed off but check if it starts your mat leave just in case!