Is my baby ok? Not eating muchi

My 15 week old is a BIG boy! He’s in the 90th percentile and never had an issue eating. He now eats on average 7oz per feeding every 3 hours. The sitter called me today freaking out and said he isn’t eating but hungry. I wasn’t home to asses him myself. I called his doctor and let her know and she didn’t sound at all concerned. She said some days babies will eat less and to only bring him in if he’s crying and is inconsolable. I have a scheduled video visit with her tomorrow and she really didn’t seem worried. I rushed home and my son was happy and playing. The sitter kept forcing a bottle and he just didn’t want it. He had 3 oz within three hours when he normally has 7-8oz in this timeframe. My sitter was panicking. I personally trust my baby. If he’s not hungry then don’t force it unless this becomes a pattern. I kept telling her to trust him and to never force food on him...she did it anyway for a few seconds which seemed like eternity to me. Anyways, he just wasn’t hungry! I’m not too worried but should I be? She has such a good heart and cares so much so she made me a bit anxious when she told me they can get dehydrated and he needs to eat! I kept telling her the doctor isn’t concerned but she said she’s gonna try giving him food after his nap. Would you be concerned? This is my first baby so I don’t have much experience but I feel like I have my off days and don’t eat much and babies probably do too?