Hi my last period period was febuary 16 20015 and i had sex with someone on the 14 of march. could that person be the father of my baby?

Longshot: Most likely the father of your baby was someone you slept with around the first of March not the middle of March UNLESS you have a very long cycle, then in that case it's definitely possible. Do you know how long your cycles are?? Good luck to you.

Hard to say for sure: if you have regular periods and you had your last period in mid February, then I would expect for you to have released an egg in early March and so a act of intercourse in mid-march wouldn't be likely to have caused the pregnancy unless the pregnancy was due to a egg that was released in early April.