I had bleeding at 16 weeks and didn't stop til 20 weeks with this one and the damn hospital made me wait til Monday for a scan, they wouldn't even put the doppler or anything on - went in Saturday night... longest wait of my life. Anyway baby was and is fine didn't give me a reason as to why. When i went for my 20 week scan a few short weeks later the Sonographer let me know i have a low lying placenta and it's needs to be checked again at 32-34 weeks, my Doc thinks that probably was the reason why i had spotting and a little red blood from 16 - 20 weeks.