Women won't forget the day they delivered a still-born. While they won't forget that they had one or more miscarriages, they won't burn a candle that day (they may well forget which day it was exactly. It won't be on the calendar). And there are certainly no candles in the toilet being burned for a discarded fertilized egg being flushed down the drain.
It is a mental, developing process. So, at some point a line can be drawn. Sure, for some people line will be at a different time than for others, but it is simply not true that there is no difference in how growing life is viewed during pregnancy. You'll have a hard time finding someone pro-abortion that will be in favor of an abortion time limit at 7 months.