Hey I Had My Daughter On May 3 2014 And

hey i had my daughter on may 3 2014 and my last period first day was january 31 2014 i have a normal 28 day cycle every month i had sex valentines day night but it was already after 12midnight unprotected then i had sex march first but it was with a condom and i was drunk but i know we had one on because i through it away . and i was pose to have my next period feb 28th right?? i took a home test on march 8 th and it was pregnant days before that i was having real bad cramps so i thought i was about to come on ! then i was sleeping and threw up a part tart > my first sonogram ever they gave me nov 7th den i took one to find out the gender it said nov 13th then i took one at 39 weeks my last month she said it was nov 22th . when one more accurate and when do you think i conceived