Low growth percentile

LJ • Baby girl born Feb 19, 2015 and second girl born Jan 20, 2017. Baby #3 due in October!
36+5 weeks and measured in at 12th percentile which is down from 35th percentile three weeks ago. I will be doing a non-stress test on Friday. If you have had something similar, can you tell me when you ended up having your baby. Were you induced?  Any reasoning for it?