one piece Ch 550- Marine Headquarters

One Piece finally came out and it was awesome! In this chapter there are a few big surprises. In the beginning of the chapter there are scenes of the four seas showing what the people thought of White beard which wasnt very highly. Then it went to marineford where Ace was to be executed. There was a lot of marines there as well as five shichibukai and the three marine admirals. It was revealed that Ace's mother Portgas D. Rogue, actually held Ace in her womb for twenty months, then died! But that wasn't even the biggest surprise. The biggest surprise was that his father was actually Gold D. Roger!!!! To me this doesn't make any sense because Luffy is supposed to be Ace's brother but how can that be possible if Ace's mother died after giving birth to Ace so how can he have a little brother? i thought that Ace and Luffy had different mothers and same fathers but now this turns everything upside down. This means that Luffy and Ace are not brothers but actually cousins, but the most confusing art is who is the son or daughter of Garp. It could be either Portgas D. Rouge or Gold D. Roger, they both have D. as a middle name so it could be either. Anyways everybody has to read this chapter now!
http://www.onemanga.com/One_Piece/550/01/