It kind of depends on how old you are. Also, was this your first iui?
I think hcg levels can indicate if there is more than one. Also, a vaginal ultrasound will tell you if there is more than one gestational sac.
Thanks for your response! Yes my HCG levels were high....26 at day 10 after my iui and 350 at day 14 past conception. However, my nurse and everything I have read assures me there is a HUGE variance in what constitutes normal for a single baby. This was our first IUI and I just turned 30 a few months ago. Our u.s. is in 13 days. Praying for healthy baby/ babies :)