Blood Transfusion any reason why this could happen again?

Hi, am 16 weeks pregnant with my second child. My first baby was induced 4 times, 11 days overdue on prostatin, pethidene, gas and air then epidural. I ended up with a vacuum birth and a lot of blood loss. I feel very scared that I will need another blood transfusion this time around even though my blood is being monitored carefully. I had to have three units of blood tranfused and then suffered palpitations terribly which resulted in ECG checks, etc. All calmed down after transfusion finished but am I am very scared of a repeat performance as I feel I missed out on so much by being ttotally out of it. Is there any reason why this could happen again or am I anxious for no reason??

Sorry if is a silly question but I can sleep thinking about it and am terrified something goes wrong. Thanks!