I lost my May baby

I was 12 weeks, 2 days today. Around 4 AM I had awful, sharp cramps. I felt a pop and a gush of clear liquid came out. About 15 minutes later I started miscarrying my baby. I had a similar experience with my 1st pregnancy at 12 weeks in March 2016. We had been struggling to get pregnant and I was seeing a fertility specialist. I got pregnant on my 2nd round of Femara + HCG trigger shot. I saw my fertility doctor every 2 weeks during this pregnancy for an US. Every US was perfect...right on target. I just saw my baby 3 days ago and he or she was moving around! I graduated to my OBGYN that day. I’m at such a loss. My heart is broken and I don’t know if I will ever be able to carry a baby full term...I just don’t understand...