Random bleeding

Niamh • 22 // Music PR
Does anyone else get a really random bleed? Normally if I get spotting it's like a tiny bit, but really occasionally I'll get a proper bleed like as if my period has started...but then it goes away after an hour?! 
Does anyone else get this?
I also sometimes bleed after sex. I went to the docs and she said my cervix looked healthy, it could just be hormonal. 
I came off the pill December 2014, and got a copper coil put in. I would've thought my hormones had levelled out by now, but is this normal for hormone free?? I went on the pill pretty young so I don't really remember what periods and stuff was like before!