Oats are completely safe and very gentle on the stomach. I was extremely cautious about my diet after my loss, but my doctor highly recommended oats for digestion.
I was so paranoid about eating anything in my first trimester, even oats! But actually, they are super safe and have so much fiber, so please don't worry.
Yes, it is very good. My mother used to make oats porridge for me in the mornings, and my doctor also agreed it's great for keeping gestational diabetes away.