I had my period on 2/20 and I had sex on the 3/6 and 3/9. On 3/11 I started to have cramps, lotiony discharge, and bloating when did conception happen?

3/6. Usually conception occurs when you ovulate. Generally that's 14 days after the first day if your period if you have a 28 day cycle. If your cycles are irregular, then it would be more accurate to determine your dates based in an early ultrasound rather then your period.