Congratz! I just tested positive today as well... there must be something in the water here! LOL
I woke up thinking I was going to start my period as well. Last night I had a little bit of cramping, went poopy 3 times, was slightly sick to my stomach (which usually happens when I am hungry, tired or about to get AF). I have also been very tired the last few days, I felt like I could pass out in the middle of the day. I even took a 3 hour nap with DS and I wanted to pass out at 8pm.
As far as the cramping it could be implantation, which could cause some spotting as well. Especially if you had it with your previous pregnancies.