I had a period that started on feb 16 or 17 and ended on the 21st. i had another one on march 9th and ended on march 13. i ahd sex with my boyfriend through out this time but on march 13th and march 18th i had sex with a blast from the past being stupid and not using protection. i found out i was pregnant on april 19th and on april 21st the doctor said i was 7 weeks pregnant. when did i concieve and who is the father?