HCG 57 to 183 is this too low

Tara • #2🌈🙏EDD 5/14/19, MC 7/13/18💔, CP 4/6/18💔, DD 1/9/17👨‍👩‍👧💖, Married 3/14/15💑💍

So I had blood drawn at 2pm on Thursday the 6/28 at 4 weeks and it came back at 57. I had my second draw 5 days later, on Tuesday 7/3 at 2pm at 4 week 5 days and increased to 183. Is the increase too slow and do numbers seem low? Or am I fine? Doctor didnt seem overly concerned and said "it increased so that is good and now we will keep an eye on it"...not sure how to interpret that...thoughts?