You could always fake it but I think honesty is the best policy. You should tell him the truth.

i had sex a few weeks ago and me and my boyfriend were having sex. he pulled it out but then he said he saw cum inside and around my vagina. he wiped it out but could i still be pregnant? he didn't use a condom and i just started birth control that same week.

u could see a dr if u feel sick in 3 - 6 wks to get blood test. but im sure wiping it out wouldnt help. and most birth control isnt effective the same week. im not sure though

if you can't be honest now you shouldn't be getting married, this affects him too especially if he has any moral standards or has a christian background. From God's point of view we are all sinners & the sin s are all sins, but we are not all dishonest, i believe if you love him you will be honest as well as if he loves you he will be rational with you, & work things out!