condom was about half way up his penis

it is possible to get pregnant. but, i wouldn't worry too much. you could get the morning after pill just to be safe. But, it will make your period weird. it could start early, late, or on time. so, if your period is late, take a pregnancy test. if it's negative, you probley aren't pregnant. worring can make your period late too. so, if your period is late, it doesn't always mean that you are pregnant.