Feeling sad....HCG didn’t double this time

I’ve gone for 6 draws starting at 4w 1d. They’ve been every other day since last Tuesday. I doubled in every single draw except for this last one. On Wednesday it was 2513 and today (at 5w 4d) it was only 4167. I feel heart broken and can’t stop crying. My ob likes to see doubling every 48 hours. I’m just so upset and feel sick. Now I have to go this whole weekend and wait until Monday to get a call from my OB. Did anyone else have multiple numbers that doubled within 48 hours and then stop doubling? I know the doubling time takes longer as numbers get higher, but my numbers aren’t that high. This was an unplanned pregnancy as my husband and I weren’t planning on any more kids (I have 3 beautiful babes) but I was so excited when I found out. Im trying to hold on to hope but I feel hopeless.