I could have posted exactly your words last week!
At about 8 weeks, I just stopped feeling pregnant. Completely. No more nausea, no more exhaustion, no more constipation, and my BBs weren't even sore anymore! It did have me a little freaked out. I kept thinking "I never did have a blood test, just POAS. Maybe I made all of it up! Maybe I'm not really pregnant! Or maybe something bad has happened to the babe!"
But then at 10 weeks, some of my symptoms came back. I've been semi-nauseous the past few days, had to take a few naps again, BBs are sore again (but not as bad as before). And I definitely know I am pregnant. No doubt about it.
I think it's going to just go in waves for a few weeks/months. I've read that, even though our bellies will look PG in the second trimester, a lot of us will loose all m/s and exhaustion, and will have to remind ourselves we're pregnant.
All is well, I'm sure. Cherish these days and weeks without the yucky symptoms!