No because you are having them for different things. You need so much of the a choice to ensure you are having enough calcium and you need so much b choices for their fibre content.
You could have half of one a choice eg milk and half of another eg cheese. Again these must both be a or both be b choices
You don't need a lot more calcium when pregnant, the recommendation is two or three servings a day so your HEs plus yoghurt, fromage frais, quark and any calcium rich veggies will be more than enough.
Hi Fatty No More - Congratulations on your pregnancy
On green you can have certain cheeses as As and Bs so in theory you could have 4 dairy healthy extras a day. Dark green veg and oranges are good superfree sources of calcium.