Problem with breeding

I have bred E-(female) monster with D+(male) ,the result are D+(Male) twice. Can anyone tell me how can i get higher rank? Do i need to breed thatE- with D- or D to get high rank of female first? Thanks for reply (sry abount my English)

Breed again until you get D+ FEMALE
Then you can breed D+ with D+ to go higher..

Breed again until you get D+ FEMALE
Then you can breed D+ with D+ to go higher..

Arr.. I see . Thx you very much, hope ill get female this time