I miscarried at 14.5 wks and carried the baby with no symptoms at all of him dying until my 16th week appt. was induced a week later and had him in the hospital.
I miscarried at 10 weeks and I had mild to moderate cramping for days then I had spotting and finally passed a pretty large blood clot. Not sure if that helps but good luck.
Some people say they knew and other people have said they didnt have a clue. My friend who miscarried at 12 weeks said she knew something wasnt right because her pregnancy symptoms..ie sore boobs and morning sickness left abruptly. I think it depends on the person. Hope your ok xx