Possible miscarriage or possible early pregnancy

my husband and I have been ttc. The week after my ovulation I started bleeding. First brown then light pink, then dark red. I am bleeding enough to need a pad. This morning I took a pregnancy test and found it to be positive. My gyn told me to go to ER, and so I rushed there this morning. No baby was found in sonogram. HCG levels 700. They said that either I am pregnant or miscarrying. That it is too early to tell. Has anyone ever been in this boat? Looking for some advice and good vibes.