My boyfriend and i had sex twice, used a condom the first time but not the second. he ejaculated the first time, not the second. could i be pregnant?

Semen on penis: Pregnancy is possible anytime semen is introduced into the vagina. If there was any semen at all on your boyfriend's penis (even pre-cum) the second time you had intercourse, you risk pregnancy.

Sex: Condoms can rupture or leak, 'not the second' could be wrong; if you don't want to be pregnant, don't ignore 'safe sex' always use protection...