Just when I thought I understood this, a curve ball gets tossed at me and I feel lost again. So I went in for the 4th u/s and b/w so far, we are at the 10th day of stims and still going for at least one more day. I get to go back in tomorrow and see how things look. So last IVF (my first) we had over 30 some follicles and over 20 of those where about the right size but we got 6 out all mature. This time, I seem to be running close to the same numbers of follicles but lining is thinner, not that this matters but AF keeps coming and going slightly which I did not know was possible at this stage. RE says as long as the lining does not decrease we are ok. I went and got raspberry leaf tea anyways (my lining went from a 6-9 over the weekend with AF still here so who knows). Ok..I am rambling. Today as we are talking about the number of follicles and how many we got last time, my RE changes the trigger from Ovidrel to HCG. I was somehow under the impression that Ovidrel is kind of the same thing. So now I am confused. My b/w should be in later today and as of Saturday I had a higher E2 that when we retrieved last time. I hate last minute changes. Any ideas on what the real difference is between Ovidrel and HCG. My RE said something kind of mumbled to the effect that a couple times in the last 15 years that it was the trigger that did not work as well. At least that is what I heard, as he was mumbling to himself.