First Miscarriage (LPD?)

I was tracking my (long) cycles before my last pregnancy and saw that I was ovulating on day 29-30 with a 37-38 day cycle. This would indicate a short luteal phase. I did get pregnant that cycle and began to have some spotting around 6 weeks 5 days; they had me come in for the US and we saw the heartbeat, everything looked good. The very next night (Friday) I went to the restroom and saw A LOT of clotting. My heart sank. The following Monday they got me in for another US and baby was gone. My husband and I are still heartbroken. 😞

Has anyone else experienced something like this? Did your doctor offer help or any treatment or testing to help the next pregnancy stick. Can LPD cause a loss as late as 6-7 weeks? I really don’t want to put my heart through another loss if it’s something as simple as balancing out my hormones. Any recommendations on who I should see/talk to?