When become pregnant is it normal to not have any symptom?

When I was pregnant with my son I had no symptoms, no clue. I had just had a miscarriage a month or so before and was wondering where the period went off to, and apparently was already pregnant again. The only thing I ended up with besides a son ( :) was a lot of swelling later on in the pregnancy; but in the first trimester I felt normal. I am in my second pregnancy now, and this time I was nauseous for about a month and then just little things.