Advice please!

I had a miscarriage at 22 weeks in Nov 2015 I started metformin on April 15 for high insulin an recently found out I have pcos. My periods have always been pretty regular. They are Always early NEVER late. And today I'm 2 days late for AF. I've had cramping for about 4 days now and headaches and nausea and the,occasional back pain. Also, a small amount of clear stretchy watery discharge for about 3 days now. And today my boobs are hurting and are heavy at times. With my Angel baby the sore boobs is how I knew I was pregnant. But I don't wanna get my hopes up or over think things. I don't know what's going on or if it a because of the metformin. Or If cramping is normal, as I had cramps with my late missed miscarriage. thanks! Help and advice please!