Need to know if i could be pregnant . not worried but need help .

my period was from the 5th to the 9th and i had sex with my boyfriend 3 times on the 15th the first time we used a condom three hours later we had sex again we went for about 10 minutes with no condom on them he out on a condom and finished 5 minutes after that . the third time was protected sex . So my question is can i get pregnant from his precum that second time . i ovulated straight after my period finishes as i have a 20 day cycle . I am 19 n i have no worries if i am cuz i am financially stable with a large family that can help out if i need any help . i just need to know if there is a chance i could get pregnant ?