Fetal Pole Question

Brittney • I`m 32 years old and have a almost 2 year old son (bday 9/3) and pregnant with our little girl (due 10/4)
Hello! Second pregnancy (my son is 16months). I got a surprise positive test last Monday. I went in for a scan today since I'm not sure when we conceived or when I ovulated
(I still don't have normal periods since I was BF'ing). My scan shows only a sac measuring 4w6d, no fetal pole yet. That's okay right? Could be totally normal? I go back in 2 weeks to check and make sure I have a viable pregnancy.