bump measurements decreased? help?

[HarriboHarribo]

So I have always throughout the whole beginning of pregnancy measured anywhere between 7-10 cm too small and have had 3 growth scans but baby is always measuring average. However the last time I saw my midwife I was 32+5 weeks and measuring 29 cm which sounded good as I had finally caught up round about to what I should be. However, I'm now 36 weeks today and due to see my midwife tomorrow, I have just out of curiosity measured my bump (well, had someone measure my bump) as when I lay down my stomach is almost completely flat. I'm getting 27 cm so in 3 weeks I have decreased by 2cm? I was wondering if this is the case what will happen? I like to be prepared. Maybe it means nothing or my measurements arent quite right but surely I should have gotten bigger in 3 weeks?

I measured consistently on the 85th percentile and was told I was going to have a big baby (always a few cm above my weeks at my 20, 24, 30 & 33 week appointments). Went back at 36 weeks and they were measuring me as 32cm so got sent in for a growth scan. She's on about the 50th percentile now and looks to be a good size.
Measuring the bump isn't the most accurate way - it could be your baby is in an odd position, also depends on your original body fat etc. Don't worry too much, you might get sent for more growth scans but they're nice and reassuring at least.