5.5 Weeks Pregnant But No Gestational Sac Thru Transvaginal Ultrasound

I found out I was pregnant ystd and have seen my gynae. She did a Transvaginal ultrasound but did not find a clear gestational sac. We can only see something very small and unclear. She said she's not convinced that's the g.s and told me to get a blood test. The result will only be out on Monday. She said the hgg level will determine how many weeks I am. I've been googling since ystd and saw lots of post which were similar case to mine are related to ectopic pregnancy. I'm so worried now. Anyone have similar experience? Its torturing to go thru this long wkend to wait for the result. :(