Vanishing Twin👶🏻👶🏻

Lindsay
Monday I went in for a Beta at 13 dpo and my level was 11. Today I went in and my Beta was 8.6. I am of course thinking the worst but Dr. said it could be due to a vanishing twin and wants me to test again Friday. Anyone else have this happen? To me this doesn't seem right or look good but we did do IuI and multiples are more common with it. Don't know what to think!