2 miscarriages - all test reports normal

I am 27y old and had my 2nd miscarriage in a row recently, hence I and my husband gave all medical tests. Blood tests(for tsh,diabetes,rubella,pcod, autoimmune diseases,and everything related to pregnancy), and we also gave blood karyotyping test. To our surprise, all the reports are absolutely normal and no issue was found. So to investigate further,we gave sperm dfi and amh tests also (reports yet to come). We are not blood relatives and neither of us have any such family history of miscarriages. I lost both pregnancies before 9th week. Not knowing the reason is killing us even more and we are now afraid to plan for another pregnancy. We both are healthy and follow healthy diet (no smoking and drinking also). I'm just thinking if this happens to anybody else too? Is this something that we need to take seriously or it was just our badluck that both pregnancies didn't get through well? Please advice. Thank you.