Worried

I'm 6 weeks today. Sometimes I feel totally fine, like I'm not pregnant at all. I was nauseous all weekend but I feel fine today. My doctors appointment is the 15th and I'm scared that I will go and they will tell me I'm not pregnant. If I haven't bled or anything I haven't had a miscarriage, right? I feel like I need to keep taking pregnancy tests to make sure. 😭 Is this a normal fear?