I am in my third month and have no nausea or other symptoms of pregnancy. Is it normal?

Yep, you're probably one of those women who have no symptoms! Lucky you. I didn't feel at all pregnant when I was with my #1 but #2 was very very tiring for me. I didn't have nausea, but I had massive headaches in the morning and my appetite was close to zero. The sight of rice makes me want to gag and I was constantly tired no matter how much I sleep. It differs from woman to woman but like Jamie said, if you're worries, bring it up to your gynae :)