I and my boyfriend had sex with clothes on.I had my underwear and leggings and he had his boxers and a thin cloth barmoda.He cummed inside his boxers.We did this on 26 of jan.I had my period due on 16 feb but i had not got it.I usually have missed periods some times they dont come for 3 long months .I had a pregnancy test done with pregnancy testing kit on 16 feb and 17 feb both showed negative results.can i become pregnant in the above scenario.