Constant worry?

Melissa • 25 and pregnant with our first little Peanut!
So I'm fairly new at this. My boyfriend and I haven't been using contraceptives for awhile and I have never been on birth control. I posted something earlier this week about brown colored spotting last week. I have never spotted and it was a week before my prospective AF
​I can't stop wondering if I am pregnant, but I haven't had many symptoms. Slight nausea, decreased appetite, and mild cramping. 
​Any insight on how to calm my nerves?