Is it just me or have others had problems with their bitch coming in to season late

I have been waiting for my girl to come into season knowing that she comes in every 8 months not 6 and still shes late:rolleyes:
I have everything ready and I am ready to go but it seems she is going to make me suffer and keep me waiting, LOL.
Is it just the time of year or is it Labs in general that are slow to come into season, she's 3 years old and this will be her first litter.
I also have a 11.5 month old and shes not come into season either, not that this is a problem but does suggest that maybe she's going to be every 8 months also, both are from different lines.