my DS is nearly 4 months , i've been trying a bottle of expressed milk almost every day for last 6 weeks. some days he will take maybe 3 ozs max, so i know he can do it, but most of the time he screams himself hoarse and just won't have it. any tips? also how about introducing a formula feed, would that help? don't want to give up BF but am a bit worried that i may be feeding him when he's 3!