Something moved during sex?

So, I'm 8w5d today and my husband and I had sex. When we were in a certain position, I felt something in my abdomen move. At first I thought I was crazy so I put my hand there and could definitely feel it. When I asked him to touch it, he felt it too. Now I'm totally freaked out that I hurt the baby. I've heard it isn't possible to hurt baby during sex, but I don't know what it could have been. Help?!?