Since my baby was born I have been expressing my milk for bedtime bottle and for times when I'm out or on the lol so sad can feed. However for the last couple of days I've been struggling... Only getting an ounce from one breast and barely anything from the other. Last week I was getting 3-4 ounces from both! Why has it changed and how can I fix it, if i can? My HV says it's because my milk is changing and therefore little ones feeds are changing and there's not a lot I can do. Any suggestions?