In need of advice..

So back in April, I had found out I was pregnant, went to the hospital to confirm it by blood test, and sure enough I was pregnant. 2 days later a clear blob had came out when I was using the RR. I had went back to the hospital, and come to find out I had a miscarriage. I was 14 weeks and I never even know. Come August, I found out I was pregnant again. When doing my ultrasound, my Dr saw the sac but nothing was inside. she said it was normal because I was barely 5 weeks. She ordered blood work to make sure my hcg levels were increasing, and they were. she requested I come back in a few weeks to do another ultrasound. So today I go back, and all we see is the sac... I should be already passed 8 weeks. she called it a failed pregnancy. has anyone ever gone through two miscarriages and then conceived after... I'm losing hope.. I feel like I won't ever be able to have another baby.