How is SMP calculated?

[LaCerbiatta]

I was told at work that it'll be based on the average 2 pays before the 15th week before baby is due.

What if I get a raise after that??? Is it not taken into consideration for calculating the 90% for the first 6 weeks?

SMP is based on average weekly earnings for weeks 17 - 25 of pregnancy. If you get a raise after that your SMP should be recalculated and backdated, see here.

That's really helpful, thanks!