Symptoms starting to fizzle…

I am currently pregnant with my rainbow baby. During weeks 4 & 5 I was having a lot of symptoms (frequent urination, light cramping, cravings, major fatigue, and VERY tender breasts) which I felt was a great sign. During week 4 my doc did HCG tests and my levels were rising beautifully. However, over this past weekend, right around the 6 week mark, the symptoms aren’t as severe and I started to get the scary feeling that I’m no longer pregnant… no spotting or anything, just a general “feeling”.

I am going in for a first ultrasound on Thursday when I’ll be 6w 5d and I’m really nervous. I know I’m early but I know plenty of moms who saw a heartbeat at 6 weeks so I’m hoping to see one just for some peace of mind.

Does the sudden drop in symptoms mean cause for concern? Has anyone had their symptoms ease up but still had a completely normal pregnancy?