vaginapagina | Worried i might be pregnant or have an STD =( (Reply)

I made this account specifically to post here.
I recently was very irresponsible and had unprotected sex with a guy while very very VERY drunk. I don't even remember how it started or ended so I am not sure if he pulled out. I also gave him a blowjob.
This happened late friday night, so more like saturday morning, and I got the morning after pill (Next Choice) on monday. (That was as soon as I could get it).
I should have gotten my period last week or this week and it still hasn't happened.
Now I'm really scared that I might be pregnant.

I also noticed that the way I smell down there is a bit different now, its almost like the way my period blood smells, and today I noticed something dark on my underwear when I went to the bathroom so I thought it was my period but when i wiped there was no blood. So (and this is gross) I scraped my nail across the dark spot on my underwear and it was like a thickish brown discharge.
Now I am freaking out that not only could I be preg but I might have an STD!
Any help is greatly appreciated.
And I know I was very irresponsible and my actions are causing me a lot of stress so please don't yell at me for being an idiot!! =/
This was also my first time eeek.
Thanks.
*Edit* I edited my post to include tags and a little information which I forgot! sorry about that.