Low HCG Levels?

My due date is 8-4-20. We got our BFP on 11-25. I'm currently 5 weeks along! I have had 2 HCG Beta tests. The 1st one was 12-2 with an HCG of 222. I had a 2nd one on 12-5 with a level of 437. The doctor says they are within normal range but low. I explained to her that I take 5,000mg of biotin and asked if that would effect the levels. She stated it wouldn't but I've found information that contradicts that. I am having a fantastic early pregnancy. No major symptoms, no weight gain, no cravings, no nausea, nothing. I feel fabulous! Should I be worried? How would you feel about this information?