If you had a hysterectomy that means you do not have a uterus anymore. Highly unlikely pregnant.
Did they leave your ovaries or was it a total hysterectomy? If you have ovaries, there is a chance of an ectopic pregnancy if by some chance a sperm met an egg. Easy enough to check, take a pregnancy test.
It’s not possible. Only way to get pregnant after partial hysterectomy is the cervix wasn’t closed completely and a microscopic opening is there, or tubes wasn’t separated and closed in the stump. It’s so rare for this to happen. Better chance at winning the lottery.