Wa'alaikumassalam, mommy. Mmg sometimes after BCG ada swollen glands under the armpit yang lama sikit nak settle, especially if ada infection, a few of us had the same worry, and our pediatricians said it's normal reaction to the vaccine but kena monitor closely. Since you've already seen the doctor and dah start antibiotics, the best thing is follow up balik with them if tak improve dalam 1-2 minggu lagi, sebab they'll know exactly what stage your baby's healing is at dan boleh adjust treatment if needed.