What you are doing sounds fine. Different things work and people have been successful using various methods (some cool temps, some don't, that type of thing).
It could also simply be that one or both of them is not ready or not in the mood. I've seen things mentioned before to try to jump-start courting like - heavy misting or placing another male's shed in the cage, but haven't tried those myself.
My personal feeling is that if they haven't started courting by now you may want to just try again next season. Really it comes down to your opinion, your feelings and your knowledge of the snakes.
My 'procedure' for breeding is mostly based on information I read in the Boa Constrictor manual and Boaphile's 1996 Reptiles Magazine article. Here's a link to the article, I highly recommend it
http://www.theboaphile.com/article.html
Of course, even though we do everything correctly to set it up for success doesn't mean the animals will perform, it's really up to them after-all.
I personally do not cool temps. Once the female is gravid, I will provide a heat pad to give her an 'extra' warm spot she can choose to use. I feed my adult boas every 4-6 weeks. I will give them a few extra feedings before introduction because I don't normally feed them once introduced.
The male goes into female's cage and usually courting will be seen in the first 48 hours if they are ready to go. If it's been a week and I haven't seen any courting, I'll take the male out for 1-2 weeks, then try introducing again. If this happens about 3 times with nothing (male sometimes stays as far away from the female as he can) then I give up on that pairing.
If all goes well then courting starts on and off (photos below). Once all courting behavior has ceased, hopefully I've seen either the pre-ov swell and/or ovulation swelling by that time, the female goes into her post-ov shed and I remove the male.
He goes back to his home and gets a nice meal for his trouble. Once female has had her shed, she also goes back on normal feeding schedule and the countdown begins. I stop feeding her 30 days before she is due. From time of introduction and courting to that last shed can be anywhere from a few weeks to a few months.
Here are some courting photos to give you an idea of what I look for, the male should be next to or looped over the female, line up his tail near hers and you may see him spurring or tail twitching. Male will take breaks, either staying on or near the female in my experience.
I hope some of this information is helpful, good luck!
