Constantly Worrying

I had my first prenatal appointment last week, and the doctor said I was 6 1/2 weeks along.  My cycles had been about 36 days, though, so I may not have been as far along as thought. However, my hcg was 60,071 and my progesterone was 20.  She said that and all my other labs were perfect. I did not have a pelvic exam because I'd just had my yearly at the end of March. The day after my spot I started spotting brown. I freaked out and called and was told not to worry, etc. since the. I have spotted pink one time, and I have both pinkish and brownish CM. I have had menstrual-like cramping since I got pregnant, but the doctor told me that, too, was normal. I have a pelvic ultrasound scheduled for tomorrow to get accurate measurements and due date, but I worry incessantly that something is wrong. I just want to hear my angel's heartbeat. Anyone else experienced cramps and regular spotting this early on and everything be fine? I'm terrified about tomorrow.