I had sex on March 28th but had a period in April and OK I had sex April 30th I didn't have a period in May but I had sex on May 30th and May 31st I took a pregnancy test on June 3rd and it said I was pregnant... so when did I conceived and the baby came on January 31st I went into labor on January 26th,if you get pregnant in march is January 31st too long to have a baby

I would say you conceived in April. If you had conceived in March and delivered in at the end of January, you would have been potentially a month over due.