My edd is 8th of february 2014 but it says my lmp is the 4th of may 2013 but i have a period the 6th of every month so when did i conceive.?

Imprecise: You are the only who knows for sure when your LMP really was, and which days you had sex on. If you are positive your LMP was 5/6, then you most likely conceived 14 - 16 days prior to that, february 16 - 18. The edd is calculated from your LMP regardless of when you conceived. I know it's a bit confusing, but that's just the way it's done. Ultrasound is helpful, but it's not exact for edd.