Everything I have read suggests 21 days for a normal season. My youngster is now day 22, so I was planning to take her out today. And then I read JeanSWs post about a bitch that got caught on day 28. So now I am in a quandary, to walk or not to walk that is the question.....
She dripped for the expected amount at the beginning, which then stopped over a week ago. I was expecting a second phase of drippage (the mop and bucket are still on standby) but this hasn't materialised. So, do I risk it or keep her in for another week? Her vulva is still quite puffy, but it didn't really shrink back after her first season and she's not really flagging.

I did take my dog out round about day 21 having given her a good soapy wash round her nether regions and a spray round with bitch spray for good measure. However, I went to quiet areas and kept her on a lead and kept a wary eye out for other dogs especially those off the lead.

I give 4 weeks for mine when in season. I still walk mine but stick to the roads where dogs are ment to be onlead.

I always keep them on lead a full 28 days as most of mine are ready in the third week or later for mating, though if they look finished I will take them to shows after 21 days after a wash and brush up, and keep away from males.

Thank you for your replies, I think I will spruce her up this afternoon and then try a lead walk later. She's been very good, but I think she's getting a little stir crazy.

lol..not common(never had one before) but I had a bitch whose season lasted 5 weeks

Oh heck, that must have gone on for ever!! Three weeks are long enough when you have a dog that loves it's walks!
I have just taken her ladyship for a walk, smelling like a tarts handbag as a result of her spruce up, and it was uneventful. Phew.