I have a 5 week old boy and just have been breastfeeding. I recently started pumping and having my husband give the bottle. We've been using tommee tippees everything was going well for about a week. The past two nights though he's either gotten fussy with the bottle or he'll be sucking but it'll go down his chin. We do it slow but it still comes out. Any suggestions?? I want him to be okay with a bottle!