I am a first time mum too and DD is doing exactly what yours is doing. She's been fully FF since she was 3 weeks old and been feeding well, wanted to be fed 150ml every 2 hours during the day and one night feed which she dropped about two weeks ago. At 21weeks I started her on solids (paed's advice) gradually beginning from 5g to the full amount of 15g once a day (mid morning) and one week after that it's like mission impossible to get her to finish her bottle. Sometimes it took me almost an hour to get her to drink the 150ml. Then this morning she absolutely refused to drink more than 90ml at a time. She's dropped from drinking about 800ml to just 580ml. I too am concerned if she's getting enough milk. I wish I could offer you some helpful advice but being in the same boat at least this could be a comfort that our babies are going thru the same phase? DD had her monthly check up yesterday and the dr said she was trekking very well but that was before she started drinking less. My only solution is at this stage is to observe her closely. So far she is quite active and is starting to roll. I just hope this is temporary. If I get too worried then I might take her to the doctor just for another check up. Hope my sharing this helps in some way?