Ok my boyfriend says he camt have kids because of a surgery whem he was younger his left ball was pushed up in his stomach n had to be pulled down.?

It was not surgery: Bringing the testicle into the scrotum improves sperm production and increases the odds of fertility (depending the age it was brought down). It also allows the health care provider to examine the testicle to detect cancer early. Most of this undescended testis are dysfunctional. He needs full evaluation and should have a semen analysis. Other factors should be considered (i.e. You as well).

Unlikely: The surgery your boyfriend is referring to might have an affect on the ability of one testicle to produce healthy sperm, but would not have affected the other. I would suggest using contraception unless a pregnancy is your goal.