A.B.
Hey, J.,
Just to reiterate what some of the others have said... I had an ectopic pregnancy and it did show up on the pregnancy test, but the line was very light (although I tested pretty early). I knew something was wrong a few weeks later, when I had *very* sharp pain on one side of my abdomen. Not like normal cramping at all, but an alarming pain I had not felt before, accompanied by some pinkish spotting.
When I later had a healthy pregnancy, I experienced period-like cramping for pretty much the whole first trimester.
Good luck!
A.