Help! Light red slimy discharge?'

Hi guys, I'm really frustrated here. I've had very slimy discharge with a few drops of blood two days ago and today it was just a little red. I shouldn't be on my period, I was two weeks ago.
I had unprotected sex a while ago but at the time I was still on birth control. About a week later I went to my doctor and she told me to stop taking the pill because it gave me depressions. Since then we've always used condoms.
Could this still be a sign of pregnancy? Or is it maybe just because I stopped taking the pill? Or could antibiotics be the reason? (I took antibiotics the last six days but they made me more sick so I stopped today) please help!