With a due date of march 1 it's def the bf if u actually calculate from ur last period ur due date would b around feb 23 so no way it's the other guy
The baby is your boyfriends or whoever you had sex with after your May 19th period.
No not the other guy as you had a period after that i would bet its ur boyfriend congratulation and if ur worried get a paternity test at birth, im certain its ur b,fs though all the dates work out to be his child x