Hi - I am doing FSH with IUI to conceive. I took the HCG trigger shot 10 days ago, but only last night my breasts have become very sore. Could this be a delayed reaction to the HCG or should that be about out of my system? This is our second cycle, our first cycle I became pregnant but had an early miscarriage. I experienced the same thing i.e. breasts sore about a week after HCG trigger shot was administered. Thanks in advance!