Chinese gender calendar

Angel
So the hubs and I have 4 boys in total, we have been trying to conceive a girl but no luck. Our youngest is 5 years old and we've been thinking about trying again. So I looked up on the Chinese gender calendar that if I conceive in March and April I'll most likely end up with a girl which I'm really rooting for. 
Has anyone ever gone by the calendar and got what they wanted? (Boy or girl)