Very hard boobs

So I'm nearly 17 weeks Sunday and my boobs are super painful and like rock hard. This is my second, they almost feel slightly engorged. Over the past 3 days they have got sore and harder. I don't remember this with my first. I'm thinking crazy thoughts like is baby still ok and alive.. Does engorged breasts only happen after baby is born ? Because I don't remember my breasts being so sore and hard with my first not until after I gave birth.