Hi, I"m new mum to be, not sure anyone can help advise on electric breast pumps. I've have been blessed with a preloved Medela mini electric breast pumps and might need to get new tubes and valves. However I have also purchased brand new Avent milk bottles starter kit. Seems it cannot fit the pump. Should I get the Avent new tubes and valves but will it fit the Medela Breast pump. I am quite clueless on what exactly to get for replacing new tubes as the preloved ones are yellowish and definitely need to be replaced. Please someone help?!