I echo all of Sabi's comments - we all love to research beta numbers ad nauseum (no pun intended...), but in reality, they are all over the board. If you have decent numbers to start (generally, 100 or higher at around 14 days post ovulation), that is a good sign, and if they increase by at least 60% or so every two days, you are doing well.
Some people say that, in addition to higher numbers showing a trend towards multiples, that if you triple or your two-day increase is way higher than predicted, that it may also indicate multiples. If you feel like doing some calculating, another website I recommend is:
As far as nausea, I had minimal signs aside from some generalized queasiness, from around 4 weeks forward. My breasts were more sore and bigger, and I became quite constipated at 5 weeks (sorry TMI!) but that is also a consequence of the progesterone most of us are on for IVF. Some people get no symptoms at all. I gather that most people who will get morning sickness, they start to get it full force by 7 or 8 weeks. I just started yesterday, at just past 6 weeks!
Hope that helps....
Baylorbear - so happy for your beta numbers - yes, high, but they are a positive sign of a healthy pregancy - think positive!!