User blog:Shawn Tiger/Is BMO a boy or girl?

In James Baxter the Horse BMO says "Oh BMO how did you get so pregnant? who is the mother? who is the father?" which leads me to question if BMO is a boy or girl.. Obviously he/she would have to be a female to get pregnant (much less refer to it) but Jake and Finn refer to him/her as "he"

Also when BMo talks he/she sounds like a girl. So is BMO a boy or girl or what?