With DS, I worked full time until 37 weeks. My last official day was the Monday after a half term but was owed time in lieu so effectively finished on the Friday before but Mat leave started after, IYSWIM? Think that depends on your head/governors. It costs a fortune for someone to take mat leave!
I was in Reception until the end of the previous Summer term then Year 3 until I went on leave after Oct 1/2 term. Both year groups were fine.
This time I am only part time, Y2 but Reception after Summer holidays and will go on leave at 37 weeks again (end of Sept).
I think how you will cope depends on how your pregnancy has been. Or how much you need the money! I wanted the maximum time with DS until the pay stopped, so worked from that. I was playing netball with the Y3s in my last week, during a heatwave and was fine.
This time, I have the added joy of SPD and the pregnancy has been harder so would have struggled to do the same (although the addition of a toddler is probably what really makes it harder!)
Congratulations 