HCG levels!

Okay so Sunday night I went to the ER to make sure my pregnancy wasn't ectopic. Luckily my little butterbean is right where they're supposed to be but something caught my attention. The dr told me I was roughly 5 weeks and my HCG Beta was 400. I started looking around and other moms at 5 weeks are clocking 1000+. Has anyone else had such a low beta and had a successful pregnancy? Kinda psyching myself out right now!!