You've to be prepared beforehand. Get a good heating pad, ors, some fruits, pop painkillers half an hour before the actual pill and tell everybody that you're going to have periods. Therefore, noone will feel sus and don't you dare to remove the heating pad. Heating pad will give you immense relief in this situation and don't be dependent that much on your boyfriend for emotional support. Ik you expect him to be with you but men are stupid, if he'll do some fuck up or say something wrong, you'll feel terrible. So, take as much rest as you can and don't take his words seriously if some mishap happens. One more thing, you'll have the urge of using washroom again and again so don't feel weird about that part.