where's my period??

I had been on about five different pills over two years and there wa s always something wrong with one. I had finally found one that seemed to have no side effects and for the first three months I had a light period that lasted about four days with minor cramps. The forth month being on it I didn't get my period not even any pms symptoms. I took two pregnancy test and they were negative. The next month I had a light period the same as before but the month after that nothing again. I assumed it would come back by the next month but still nothing. I took about five tests all which came back negative. I decided about three weeks ago to go off the pill entirely because I felt like it had messed with my body and emotions too much. I still haven't bled and it's really starting to worry me. I took another test two days ago and it was negative. I've had some minor cramping but I usually experience some in the middle of my cycle anyway. My boobs are a little sore today which used to happen before I was on the pill and I'm bloated so I'm hoping that it will happen soon. It's very worrying right now and I've been very stressed which I've read can cause periods to go away. I just don't know what to hink or do. Does anyone else have this problem or have any advice??