help meeeeee

Ok my period was deb 1st thru the 5th had sex feb 19th with boyfriend broke up with me had sex with guy number#2 feb 24th  march 1st took a pregnancy test positive march 24th 6weeks 4 days  in so confused who could be father ....the doctor said that my last period was wrong that I couldn't be the first had to be the 7th but I wrote down my last date so I know it was the first helppppp!!!!