I know you said you didn't want to wean yet which is undetstandable, but if you are still night feeding stopping or cutting back on just that apparently usually works for most women. Going any longer than 5hrs between feeds is said to work. Seemed to be fairly accurate for me as ds1 was sleeping through at 6wks & I was pg again when he was 4 1/2mths! Personally it seems to take around 3mths from baby sleeping through to ovulate again. Hope that helps.