What Does Teardrop Shaped Gestational Sac Indicate?

I am about 5 wks pregnant. I went in for an early scan today due to a prior miscarriage that was 18 mos ago and brown spotting during the week of when my period would have been due. My ultrasound revealed a teardrop shaped gestational sac with a yolk present. The brown spotting has subsided. Are there any chances this pregnancy will be viable with all things considered?