6w2d and no morning sickness???

I had rather violent morning sickness with both my boys (6&5) and it started before my period was even late, so I'm guessing I was sick at around 3 1/2 weeks pregnant. Threw up constantly until around 15 weeks pregnant with both, and the nausea continued for a few weeks after that. So it may be no shock that I'm concerned I'm not sick at all right now! While I'm happy I've only had some mild nausea so far, I keep waiting for the morning sickness to kick in and nothing. Is that a bad sign, especially given the contrast between my boys and this pregnancy? I am using midwives and a birth center so no appointment until the end of August.