Heart shaped uterus & maybe twins?!?!

I'm 16w 2d now. At my 7w ultra sound I was told I had a heart shaped uterus and that due to the shape I could have a second baby hiding that might take a while to be seen. Has anyone had this happen?   I haven't had another ultra sound yet. From 8w to 14w I was in bed rest and home health for severe morning sickness. (Lost 16lbs, had a Zofran pump, & had IV fluids at home). The last 3 visits the nurses have had trouble finding a heart beat with the Doppler. And when they do they swear they hear two but aren't 100%. My OBGYN wants a MFM to comanage and do ultra sounds now. I have my first scan with the MFM in mid November. It's driving me crazy not knowing if there are two babies. My husband is convinced there are two since my belly is larger than friends who are 2-4 weeks ahead of me. I have constant very painful cramps my Dr says are normal.  But they make me worry that baby/babies may run out of room too soon. I sleep almost all day due to constant fatigue. Basically I'm only  up to pee and eat. I eat 5 times a day and only gained back 2 lbs in 3 weeks!  My legs, arms, and face are loosing weight while belly is bigger every day. Seriously almost can't see my toes now days!  Im also wonder if if its not twins why am I so big but haven't gained any weight. I also have Ankylosing Spondylitis, IBS, & Hypothyroidism.