My symptoms have pretty much vanished

So I’m 6 weeks 6 days today and this week has been bad. I’ve had a none stop headache, hard core nausea from when I wake up to right about dinner time, and sore boobs all for 4 days straight. I’ve even lost a couple pounds from lack of appetite though I’ve been making sure to drink lots of water. Then I wake up today with hardly any symptoms at all. Is this normal? I don’t want to freak myself out but just wanted to see if this has happened to anyone else. I’m afraid I’m gonna get ninja attacked with symptoms again soon.