UK moms - maternity pay/long term sick

Hi moms
This is a question about if you've been off during the qualifying period for SMP with pregnancy related illness, have you still received SMP?
I'm worried that if I continue to suffer Hyperemesis from now until I give birth I won't get maternity pay. I work for the NHS, so I'm not entirely sure if there is an exception or not but the worry makes my sickness worse.
Thank you