Not me, sorry. But I have an input anyway if it's okay
The best source is naturally the Sun on your entire body in the middle of the summer, middle of the day (no sunscreen, but gradually increasing the time you spent in the sun to prevent burn).
Supplement should be in the form of D3, NOT D2. And yes, K2 is important with vitamin D (K2 is in fermented foods, some hard cheeses and free range butter). Also eat the pill with some fat, because vitamin D is fat soluble.
I suppose if you don't take more D3 than one pill a day (35 mcg) in the beginning of your pregnacy, then there is no risk of oversupplementing.
And never supplement with vitamin A. It is easy to get enough from food (liver and carrots ex.).