LMP date for pregnancy after D&C?

I had a D&C for a missed miscarriage on 3/20 and never got a period before my positive pregnancy test this past Saturday (4/29). When scheduling my appointments the RN said they would mark my LMP date as 4/2. That seems late to me, as I definitely feel more than 4 weeks pregnant. How did other people initially get their pregnancies dated post MC or D&C and how many weeks off was it (if at all)?