Luteal phase defect & IVF

Hi there, I have started the process for IVF. I’ve had an initial consultation, blood tests, hycosy and am returning for results next week. I’ve been reading about luteal phase defect and believe this could be affecting my fertility. I ovulate on day 21, then get my period on either day 27 or 28. My period is 2 days long. We are trying to decide whether to do IUI or go straight to IVF but from what I understand, IUI will be pointless anyway as chances are the embryo wouldn’t have long enough to attach to my uterine lining before my next period came anyway? Has IVF helped anyone with this problem?