 [ Symptoms ] when did i get pregnant if im due february 16th 2013  i had sex on may 21st the 26th and several days after what day did i conceive if my period usually lasts 5 days every 28 days or so [ Disease ] hi your find out by reading up on periods through pregnancy happens but there just short 3 day periods and these go all through your pregnancy but if this is some vaginal bleeding showing fresh red blood if that is the case then doctors asap hope this helps good luck