Yeah, I went through that a week or so ago too. When I first found out, I was about as far along as you, and I didn't feel pg at all. (To be honest, I still don't most of the time.) But I had a pretty busy weekend last weekend, and I got all crampy, and I was sure I was miscarrying. But I never even so much as spotted, and things are all right now. I was told it's your uterus stretching, and it's normal. It happened more if I was particularly tired. So, I rested when I was tired, didn't strain myself too much, and watched for spotting. None came, and I have sporadic tiny cramps now, but nothing that worries me.