Rh negative

My husband and I have been trying to conceive for almost a year. I've had 3 miscarriages this year alone, so far. My longest pregnancy has only been 6 weeks. I haven't gotten a straight answer from any doctor or specialist I've seen. Half tell me I need to get a RHOgam shot before I am ever pregnant. The other half tell me that I won't need the shot until week 28. So my question is for anyone who is RH negative and have conceived successfully. What was your experience and how did you conceive?