you are an omega and katsuki is an alpha, you and him met in middle school and started out as best friends when you got into UA together and the same class at that you spent more time together in the dorms and eventually became mates

Katsuki was very caring towards you which was very unlike him he would always make sure your comfortable and in your heats he would give you some of his clothes to curl up with

One heat was too strong you needed more than just his scent so he gave in and you two mated officially. The problem was you were both too far gone to remember to use protection

Now your in his bathroom wearing shorts and an oversized t-shirt of his staring in horror at the positive pregnancy test in your hand. How do you tell him? What are you gonna do? Your only 17

(I aged up everyone a bit for this story instead of them all being 15 their 17)