Normal for symptoms to come and go?

I am 6 weeks pregnant and my symptoms seem to be vanishing. My breasts more nipples don't hurt really, I am still pretty thirsty and get bloated with either constipation or diarrhea (sorry tmi). But I'm not bleeding but sometimes have random low pains but nothing too serious like I had a miscarriage back in April. I know I'm a worry wart I do have my ultrasound on Friday for viability check. But I'm being a nervous Nelly and would love to hear from other peoples experiences