We Want To Have 1 Litter

Question
QUESTION: Hi Cassie.... We have female yellow Labrador Retriever, and she has just today (wednesday 3/19/08) started spotting. We want to 'mate' her with this male yellow lab (Max)... So that we can have 1 litter of puppies.  My question is... When is she MOST FERTILE, so we know when to put these two Labradors together so that our female will hopefully get pregnant.

ANSWER: How old is she? If she is under 1 1/2 years of age, then please be a responsible pet owner and wait until she's older to prevent health coomplications from both the pups and mother. Have you done all your homework? It took us 2 years before we finished ours. There are so many pups in the world in need of homes...please be sure you know what you're doing first!

---------- FOLLOW-UP ----------

QUESTION: She is just over two years old. And yes, I did do my 'homework' on this matter, because I am in fact a Responsibe pet owner... And found out that the female needs to be at lease two years old.  So we have waited the appropriate amount of time, and have found a AKC yellow labrador male (just like our labrador), who will be a fine 'suiter' for our female.  And we already have good people (with good homes) that want the pups... And we are going to keep one male pup. So in answer to your question... We are, in fact, 'responsible' pet owners. With that said... Could you please answer my 'Initial' Question: When is our female most fertile in her 'Cycle' that she is now in?   Thanks, Michele

Answer
    Thank you SO much. I apologize if I sounded rude, but there are so many people out there who go "Awe! what a cute puppy! Let's breed our dog." and next thing you know, almost the whole litter ends up in the animal shelter along with the mother.
    The most fertile period varies dog to dog and is why some breeders attempt to progesterone test to help pinpoint fertility (though testing is not 100% reliable but can help). The fertile period can last about five days and may begin approximately nine to ten days after the onset of heat. However, onset of fertile period can vary after the start of the heat cycle. (Courtesy of petpeoplesplace.com)
    Hope that answers your question!