It varied every pregnancy. I've had it earlier than 6 weeks before...and then sometimes it didn't come until closer to 9-10 weeks.
I've started to get pretty nauseous the last few days, and I'm 5 weeks 2 days. Haven't thrown up yet, but I have a feeling by the 6 or 7 week mark, I'll be adding that to my list of symptoms.
somewhere 6-8weeks. im not sure exactly.