HCG level

Brittany • Mommy to a beautiful boy 6/8/17, Pregnant with baby girl due 9/11/19
I had my blood tested yesterday at 4weeks and 1 day, and I called the doctor today and she said it was 150. She said that is low so she wants to retest next week, but then when she realized that I was only 4 weeks she said that could be completely normal. It kind of freaked me out though. Is 150 around the level any one else got around 4 weeks +1?