Hcg numbers really different this time

With both my boys, both singletons we are pretty positive (had ultrasounds with them both at 5 wks), my hcg numbers were really high with really fast doubling times even over 1200 ( I think Ds1 was 29 hrs and ds2 something like 27 hrs).

This time my hcg numbers have been perfectly normal 67 at 12 dpo and 571 at 18 dpo--46 hr doubling time approximately. I know its still normal and every pregnancy is different but having the numbers and doubling times so much lower this time is freaking me out a bit even knowing they are perfectly in the average range. 5 wks tomorrow so not much to do but wait for my first ultrasound at 6 wks, but I was just wondering if anyone else had a similar experience with numbers very different? Thanks!

Yes I've seen this happen to tons of people! As long as it's in normal range and doubling, that's what counts. :)