Low Progesterone/Slowly rising HCG

Tawny
My first blood draw on 4/19 was HCG-6, progesterone <1. On 4/22 HCG-36, progesterone <1. Started me on oral Prometrium. Blood draw on 4/25 HCG-38, progesterone 58! Supplement is doing its job, but anyone have any experience similar with slow rising HCG? They think me only about 4 weeks along. I have irregular cycles and took the test on a whim bc of random spotting so we caught it pretty early on. Getting more blood work tomorrow. Just hoping for the best.