hcg rising but not doubling .. any advice please

J.

My hcg has been all over the place and even dropped then rose again and I don't know what's going on waiting to hear from my doctor. After my second blood test on what i think was 18 dpo he said it's a chemical pregnancy so just wait for my period.

1st draw 15/16 dpo- 45

2nd draw 2 days later- dropped to 36

3rd draw 2 days later last friday- doubled to 74

Today's draw 2 days later- only rose to 97

Could you share any experiences or tell me what you think? Everything from it dropping to rising to rising and not doubling is so troubling to me.. Ive had 2 miscarriages before and 2 live births. thank you