Do YOU know what brought on FMS?

I'm pretty sure for me it was my second pregnancy. I had 2 big boys (9#3 and 9#12 at 39 weeks) I had terrible hip point in the last month of the last pregnancy and both babies took years to sleep through the night consistently. So for a long time as the early symptoms were showing up, I attributed it to being sleep deprived and having 2 active boys. But once my son was 4 and sleeping AND i started getting pain at the edge of my joints and my muscles were getting weaker is when I started thinking something was not right.