im 5 weeks 1 dat pregnant. ive been bleeding for 7 days. my first ultrasound should i have 1 sac with nothing in it. my second ultrasound i nwas told i was having a miscarrige. but the next day they did blood work & it should nothing wrong, no miscarriage. my third ultrasound should 2 sacs. twins. now 2 day i had another ultrasound & they see 1 sac with a yolk sac in it & the other sac empty.so im back to maybe miscarring 1 or 2. they no nothing. does anyone no anything about this. could it be the other yolk sac just hasnt develop yet? or am i losing one of them. i dont understand whats going on. any help out there??