Possible MC. 😩😖😔

I'm wondering if anyone else has had a similar situation. Here is a little background info leading up to today.

1st pregnancy - Natural MC at 6 weeks

2nd - successful

3rd - Dr thought I was having another MC from weeks 7-10. Only an empty sac at 7w2d. HCG wasn't doubling. Went back at 10w4d and measured correctly to the day ending in another successful pregnancy.

4th (now) - LMP 5/5/17. BFP 6/1/17. Had my first prenatal appt with a new doctor today. Abdominal ultrasound measured 5ish weeks. No heartbeat. Uterus measured an estimated 10w. Quant HCG 45K today. I go back for labs again on Thursday.

Anyone have any similar situations?? Trying to remain positive, but I'm 99.9% expecting the worst. 😔