I conceived one cycle after DTD 3 days prior to O so it is certainly possible. Implantation wouldn't happen until probably at least 7DPO so any cramping before that would be associated with Oing. Very few women experience dizziness that early in pregnancy but it I guess it is possible. I haven't heard of sore gums being a pregnancy symptom but bleeding gums certainly is.... I had them from week 3 of this pregnancy. You never know some people do get lucky first try.