Can Low Blood Sugar Affect Fetus Heartbeat And Cause A Miscarriage?

Hi I had a scan at 7 weeks pregnant and saw a heartbeat. 2 days later I experienced pin prick pains across my belly button and a very very very small brown discharge so I went for another scan. They couldnt find a heart beat and have told me to go back in a weeks time. I havent had any further pain but a slimey discharge with only a spot of blood. I have polysitic ovaries and I am also diabetic. Unknown to me at the time of the scan my blood sugar was extreamly low and I wondered if this could have any affect on the lack of heartbeat or is miscarriage inevitable?