When I was around 10wks same thing happen to me Dr said I had a thin lining tat why I bleed and its normail if I bleed non stop or cramp to call so
I wouldn't worry much about it, unless you start bleeding a lot or cramping along with it. With my first pregnancy I bled after sex some, but a little bleeding early in pregnancy is normal as long as there isn't cramping along with it (in that case call your doctor). Cramping & bleeding are normal as long as its one or tthe other and not both at once. Good luck!