Help?? am I?

C
So, I started bleeding about 6 days before my 'scheduled' (according to the <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> app) period. I normally have a heavy flow, with lots of blood clots, and VERY painful cramps. (I also have endometriosis) My period is pretty much normal for the most part, so getting it 6 days early is a little startling for me. I'm not on any BC. I haven't been on any for over a year. I did have unprotected sex recently (while I was ovulating) BUT, this time the bleeding was WAYYY lighter, with very little cramps. It hasn't necessarily *felt* like my normal period, i usually get sick and like I said it's always heavier and more painful.
*ive had a misscarriage before, so I HIGHLY doubt this is a miscarriage. It's NO where close to the pain I endured during that time.*
Well, the other day I took a pregnancy test. (One of those $1 ones, if it matters) and I waited the few minutes and only one line showed. Well, today as I was cleaning my room and taking out my garbage, I checked it again and there was a faint line (I have a picture if anyone needs to virtually see it to be able to help out). I read the back of the box & it said not to read it after 10 minutes due to it won't be accurate.. but then I just finished looking it up & people have said that they've been through the same thing & they've been pregnant.
The main reason I'm wondering is because after the test showed negative, I decided to have a few drinks over the next few nights (I figured why not?) but now I'm wondering if there's a possibility that I could be??? Should I buy another test? If I *were* pregnant, I'd be 4 weeks today, if that..