Had pregnancy symptoms after my boyfriend ejaculated in me 3 different times but then period came extremely late and unexpected ! what happend?

Two possibilities!: First, your period may have been late. Second, you may have had a miscarriage. No way to differentiate at this point, unless your HCG levels are still elevated. But why have unprotected sex, not being married. A child without a father is at tremendous disadvantage in life. Please, don't let this happen to you or your offspring. This is not a women taking care!