Sciatica @ 16 weeks? I work for Boots so on my feet every Sat for 7.5 hours. I had to take Sat just gone off?

as I literally couldn't walk for the pain. On Saturday night, even though I had barely spent any time on my feet, the pain was so bad I was nearly in tears. My doc has referred me for physio so waiting for date to come through for that. In the meantime, how can I get my work to suspend me until my maternity leave starts?? It's pointless me being at work as they've already banned me from lifting due to bleeding early on.