There's nothing wrong with having kids close together. I've given birth 4 times in the past 4 yrs. That said, my DD2 died b/c of a fatal birth "defect". I got preg w her when DD1 was 6 mos. I will always wonder whether my body was ready for another preg and if that was part of the reason for the "defect" and ultimately her death. If you do plan on trying again soon it wouldn't be a bad idea to have blood work done to check all your levels on important nutrients just in case.
Holly, mommy to 6 ~ 4 on earth 2 in Heaven