Hi! I had my blood draw this morning after a positive digital read and went to the doctor this morning. No results until tomorrow. But the doctor wanted to do a vaginal ultrasound to see if he could see the "sac" although he thought it was early. What is this sac? He said he was able to see it which is good but to wait until next week and he can see it better. He also said he could not say 100% that it didn't mean it was my period (I'm on day 46 of my cycle and had a positive digital) but of course that freaked me out. Has anyone had similar experiences?