are these safe to take while pregnant or do I need to wait until he's born?

I would wait, you never know how big or small your supply will be and taking them too can lead to overproduction which leads to clogged ducts, mastitis and a lot of discomfort

@showersoverflowers, thank you :)

They can lower your blood sugar quite a bit. I would wait. drink tons of water for now and eat rolled oats