Help! Haven't gotten period!

So I had unprotected sex on the 21st of March and still haven't gotten my period yet! This doesn't happen often for me I don't have sex all the time it's always months apart I was a little too drunk that night and didn't bother to use protection :( I took a morning after pill but it was literally 5 days after which you can take 1-5 days after sex but it isn't as affective as the first day we were being safe but I rather not take any chances :( any advice for me please I'm freaking out too scared to take a pregnancy test just yet