Symptoms around nine weeks?

Has anyone else noticed a change in symptoms around 8-9 weeks? I went from daily nausea (starting around 5.5 weeks) to four days of vomiting last week, but now the nausea has eased up and my appetite has returned. I'm still increasingly exhausted and my boobs are sore, but the lack of nausea is a little worrisome. I saw the baby and heartbeat on a scan last week, but I'm still terrified of having a miscarriage. Has anyone else gone through anything similar?