My question is that my girlfriend and I have relationships ...

Well my doubt is that my girlfriend and I have sex with condoms and besides she takes contraceptive from Cycle 21 to regulate menstruation. And the doubt is the possibility of her getting pregnant if I ejaculate once and clean with a cloth and the penis comes in contact with the underwear and soon after I go to wash the penis and not change the underwear and the penis comes in contact with the Underwear is there any possibility of her getting pregnant? Please, if you can answer me, thank you!