Positive digital with only 4 hcg on bloodwork?

L

Hi! I’m 4 weeks + 1 day, 6th pregnancy, and I only have 2 babies so you do the math. 😔 I was so excited today because I had a digital positive!!! And I went in for bloodwork due to my previous losses and my OB didn’t call me but put into my chart online I have “super low levels” in the comments. My hcg and progesterone were both only at a 4. How could this be if I received a digital positive before I even went in for bloodwork!?!