Is it possible to have implantation bleeding 3 days after intercourse. I remember I had a bleed on 21st of November after having intercourse with the boy on 17th of November. It lasted on and off bleeding until 26th of November I think. Don’t know if was normal period or not , but I have such bad anxiety just now about who the father is off my baby and just trying to get as much information as I can to ease my mind before my 12 week scan. Boy on 17th of November was a mistake and I know if there’s a chance it’s his and needing to tell people etc I’ll be heartbroken. I just really don’t know and this site seems to be so good at giving advice