7 weeks and 1 day pregnant, symptoms all gone today?

What you're experiencing is normal. Today you may feel fine, but tomorrow you could be paying homage to the porcelain throne all day. Missed miscarriages are pretty uncommon; about 1% of pregnancies end this way. You actually have a greater chance of naturally conceiving twins than of having a missed miscarriage. The chance of miscarriage in general goes down dramatically once a heartbeat has been detected.