HELP! Late period

So I'm about 6 days late, which I'm normally late when starting my period but not this late. I'm having period symptoms but they come and go. The last time I had sex was about 3 weeks ago and my boyfriend and I used a condom, which we always do and he always pulls out. We both know that nothing went wrong with the condom but I'm still just so worried. Also, in the last week I consumed a lot of alcohol, because I was on spring break and the last time I had drank was new year. Could this be why I'm late???