Overeating and quick weight gain

Hi all, I've been eating more than I need everyday for the past week. It's a little uncontrollable, as in I just keep on eating and don't stop when I'm feeling full. I've gained 3kg in less than a week, which scares me 'cos it's a bit too fast. I'm in my first trimester, week 10, and I know most people don't even gain weight during first trimester. I'm wondering if anyone's experienced the same as me, and if it is dangerous to gain weight at this rate?