I have recently slowly weaned my 9.5 week old onto formula feeding. I did it slowly from 1 formula feed a day from 6 weeks, to two a day a week later, until just breastfeeding first and last feed of day, and at the weekend tried to breastfeed baby and not much milk was coming from either breast - baby was hungry almost immediately after the boob feed. I have now been feeding baby formula feeds at all feed times the last few days. Baby is very happy and feeding well. My boobs have been aching today, the right one especially which is more sore than the left. I am not sure what this means as boobs were fine and not full at all a couple of days ago. It is an achy feeling, I let some of the pressure off by hand in the shower this morning as they felt a bit full - where did the milk come from when they had been so very empty? I had thought no milk was being produced as they had been so empty a few days ago hence the full bottle feeding now. Does anyone have advice on how to relieve the achy feeling? Have I done the transition incorrectly? It was how I had been advised so I'm a bit worried. I don't have a fever so don't think it is mastitis. There is no redness. Just twingy achy feeling particularly in right breast. Is this normal during this breast to bottle transition?