Low levels normal?

I recently got a BFP on Wednesday which would’ve been 12DPO. I had bloodwork on Thursday at 13DPO & my level was only 17.45. Which makes me so nervous. Also I tested at 10DPO and it was a BFN. So was I just tested right after implantation? Makes my due date Feb 6th since I have 33 day cycles? And was on Clomid as well this cycle.

I have been testing every day since just to make sure it’s progressing. I’ve had a few mild cramps so far. No bleeding so far. & I’m trying to take it easy. Anyone have any advice or something similar?