I'm on the birth control and last month I ended my period early(stop taking sugar pills and took active pills a couple days after getting my period) I've then been on anti-biotics, missed a pill and taking my pills late. I had unprotected sex and went off my active birth control a few days after to see if I would get my period, a few days later I got a dark discharge for 2 days and a half, it mainly looked like clumps and a few drops of blood. When I first got this discharge I took a pregnancy test but at this time it was only a week after unprotected sex, the result was negative but I found out it was too early for a result. So I'm curious if this discharge could be left over from my last period and I could possible be pregnant? Or this discharge could be spotting? Or even a combination of spotting and left over period?

It's really hard to say. Brown discharge is usually old blood. Usually lining or other tissue.

You've also set yourself up to get pregnant on the pill through antibiotics and missing a few pills. So there is a real chance of you getting pregnant.

Where do you go from here? Talk to your doctor. You might have to go off until you get your period and can start controlling your cycle again. If you miss your period by two weeks then you should take a test at that point, not before.

There are a lot of ifs here, nothing certain. Good luck.